Alessandro Sacchetti

• PhD
• Professor (Associate) at Politecnico di Milano

A new exotridentate ligand, 1,3,5-tris(2-methylpyridin-4-yl)benzene (mTPB), was synthesized and self-assembled with ZnBr2 in the solid-state via mechanochemistry (i.e., neat grinding (NG)), followed by annealing. The amorphous phase generated by NG transformed into a crystalline structure corresponding to a 2D MOF (1) through an amorphous-to-crysta...

For a long time, the leather industry has considered the chromium tanning process to be the easiest and fastest way to treat raw hides and transform them into valuable products. In the last few decades, increasing attention has been paid to the potential oxidation of the trivalent chromium in tanned leather. This happens for many reasons, such as t...

A collection of peptidomimetics characterized by having an aspartic acid motif embedded in a rigid hydantoin heterocycle are synthesized through a sequential multicomponent domino process followed by standard regioselective deprotection/coupling reactions based on acid–base liquid/liquid purification protocols. ¹H nuclear magnetic resonance experim...

Bispidines are a family of ligands that plays a pivotal role in various areas of coordination chemistry, with applications in medicinal chemistry, molecular catalysis, coordination polymers synthesis, and molecular magnetism. In the present work, triazole moieties were introduced using the CuAAC click-reaction, with the aim of expanding the number...

Agarose hydrogels are three-dimensional hydrophilic polymeric frameworks characterised by high water content, viscoelastic properties, and excellent ability as cell and drug delivery systems. However, their hydrophilicity as gel systems makes loading of hydrophobic drugs difficult and often ineffective. The incorporation of amphiphilic molecules (e...

The (eco)design and synthesis of durable heterogeneous catalysts starting from renewable sources derived from biomass waste represents an important step for reducing environmental impacts of organic transformations. Herein, we report the efficient loading of Pd(II) ions on an eco-safe cellulose-based organic support (CNS), obtained by thermal cross...

The treatment of used vegetable oil (UVO) with seven different adsorbents and through two different procedures (stirring and gravity filtration) was explored. Important differences in terms of density, turbidity, electrical resistance, free fatty acids (FFAs) content and relative fatty acid distribution were observed. Different outcomes were shown...

Nanogels are nanometric three-dimensional structures formed by chemically or physically cross-linked polymers with hydrophilic or amphiphilic macromolecular chains. Biocompatibility, biodegradability, water solubility and nontoxicity are the properties of these colloids that make them very interesting to be used in biomedical fields and especially...

The synthesis of a collection of enantiomerically pure, systematically substituted hydantoins as structural privileged universal mimetic scaffolds is presented. It relies on a chemoselective condensation/cyclization domino process between isocyanates of quaternary or unsubstituted α-amino esters and N-alkyl aspartic acid diesters followed by standa...

In this work, 1-(1-benzyl-1H-1,2,3-triazol-4-yl)-N,N-bis(pyridin-2-ylmethyl)methanamine (1), a ligand belonging to the DPA family, was coordinated to La(III), yielding compound La-1. The structural and spectroscopic properties of the complex were analyzed by experimental and theoretical methods. The structural characterization of La-1 was described...

The efficient synthesis of a tetradentate diol-bispidine-based ligand and its metal complex with Zn(II) is here reported. The single-crystal X-ray diffraction (SC-XRD) analysis of the Zn(II) complex allowed the characterization of the coordination sphere around the cation as a distorted square pyramid and confirmed that the bispidine core was in a...

In the last two decades nanogels have emerged as very promising and versatile biomaterials suitable for a wide range of applications. Their features such as large surface area, ability to hold molecules, flexibility in size and water-based formulations have ensured them great recognition as drug delivery systems with various in vivo applications wh...

Herein we report the synthesis of cellulose-based metal-loaded nano-sponges and their application as heterogeneous catalysts in organic synthesis. First, the combination in water solution of TEMPO-oxidized cellulose nanofibers (TOCNF) with branched polyethyleneimine (bPEI) and citric acid (CA), and the thermal treatment of the resulting hydrogel, l...

Using mechanochemistry by grinding TPB and ZnBr2, an amorphous poly-[n]-catenane of interlocked M12L8 nanocages is obtained in good yields (∼80%) and within 15 minutes. The mechanical bond among the icosahedral M12L8 cages in the amorphous phase has been demonstrated by single crystal XRD, powder XRD and FT-IR spectroscopy following an amorphous-to...

Biphasic Porous Structures In article number 2100991, Fabio Pizzetti, Filippo Rossi, and co-workers report biphasic porous structures consisting of monomer (hydrophobic, that can polymerize in bulk condition) and water can be formed simply by mixing the system using colloid nanoparticles without the typical presence of surfactants. The produced sys...

In this work, the use of DPA-triazole (DPA = dipicolylamine) molecules as ligands for metal catalyzed organic reactions has been investigated. A small library of ligands has been prepared by a CuAAC (click reaction) between propargyl-DPA and different azides. For a selected ligand the complexation with Zn(II) in solution has been investigated by NM...

Bicontinuous jammed emulsions (known as bijels) are Pickering emulsions where oil and water are both continuous phases. These interconnected structures, stabilized by colloidal nanoparticles at the oil–water interface, have been used in a wide range of applications. Among these, catalysis and encapsulation of solutes has showed promising potential,...

Reactive microgliosis is a pathological hallmark that accompanies neuronal demise in many neurodegenerative diseases, ranging from acute brain/spinal cord injuries to chronic diseases, such as amyotrophic lateral sclerosis (ALS), Alzheimer’s disease (AD) and age-related dementia. One strategy to assess and monitor microgliosis is to use positron em...

The selective formation of the heterocyclic salt ((1,4-dioxane-2,5-diyl)-bis-(methylene))-bis-(triphenylphosphonium) chloride was observed when epichlorohydrin and triphenylphosphine were reacted in CH2Cl2 at room temperature. Slow evaporation from a mixture of ethanol and ethyl acetate allows to isolate monocrystals of the heterocyclic phosphonium...

Polyamides, obtained from step-growth polymerization between dicarboxylic acid and diamine, are very important polymers used in many different industrial applications. In addition to the many advantages typical of this class of polymers, among them high mechanical performances together with chemical and thermal tolerance, the absence of moisture ab...

In this communication, we report on the use of deep eutectic solvents (DESs) for processing nuclear waste, with a view to selectively recovering minor actinides (MA) from highly active raffinate solutions. DESs are an interesting new class of green and eco-sustainable solvents. Herein, a representative family of DES was tested as a co-solvent for M...

The [3,7]‐diazabicyclo[3.3.1]nonane (bispidine) structure is found in several interesting naturally occurring alkaloids. The most representative components are the tetracyclic alkaloid (−)‐sparteine and the tricyclic (−)‐cytisine alkaloids. Their biological activities have been known for a long time. In the literature, different syntheses of both t...

Nanogels are a central class of biomaterials widely used in the field of drug delivery for the treatment of different pathologies such as tumors, cardiovascular diseases or central nervous system disorders. The great peculiarity of these systems is that, if properly surface functionalized, they are able to target specific body tissues and exploit p...

Targeted drug delivery is currently emerging as a promising approach to overcome the limits of currently employed administration techniques. The most convenient methodology to control drug delivery is the application of stimuli-responsive materials, which can release drugs only when required, to remotely controlled microdevices able to navigate hum...

Ivabradine (Corlanor®), is a chiral benzocycloalkane currently employed and commercialized for the treatment of chronic stable angina pectoris and for the reduction in sinus tachycardia. The eutomer (S)-ivabradine is usually produced via chiral resolution of intermediates, by employing enantiopure auxiliary molecules or through preparative chiral H...

MOFs, (the acronym for Metal-Organic Frameworks) are a quite new family of materials resulting from the combination of organic ligands and metal ions. The coordination between the metal centers and the organic scaffolds give rise to complex assemblies which can develop into coordination polymers from 1D to 3D structures. These materials are usually...

Astrogliosis has a unique reaction during spinal cord damage, with helpful or adverse impacts on recovery. There is consequently a pressing need for treatment to target activated astrocytes and their unsafe response after injury to ensure some preservative effect during the progressive damage. We specifically developed and characterized a functiona...

The Cover Feature shows a highly porous cellulose‐based nanosponge (CNS) used as a recoverable catalyst for Henry and Knoevenagel reactions. This material is obtained by cross‐linking TEMPO‐oxidized cellulose nanofibers (TOCNF) and branched polyethyleneimine 25 kDa (bPEI) in the presence of citric acid. In their Full Paper, L. Riva et al. describe...

Plasmonic nanoparticles (NPs) are exploited to concentrate light, provide local heating and enhance drug release when coupled to smart polymers. However, the role of NP assembling in these processes is poorly investigated, although their superior performance as nanoheaters has been theoretically predicted since a decade. Here we report on a compoun...

In the last years, nanogels have emerged as one of the most promising classes of novel drug delivery vehicles since they can be employed in multiple fields, such as various therapeutics or diagnostics, and with different classes of compounds and active molecules. Their features, such as a high volume to surface ratio, excellent drug loading and rel...

The Henry reaction was performed using microwave heating within the deep eutectic solvent (DES) choline chloride/urea (ChCl/urea) which acted as both the catalyst and solvent for the reaction. The optimisation...

The expression of multidrug resistance P-glycoprotein (P-gp) by cancer cells represents one of the major drawbacks to successful cancer therapy. Accordingly, the development of drugs that inhibit the activity of this transporter remains a major challenge in cancer drug discovery. In this context, several new ecdysteroid derivatives have been synthe...

The conformational isomerism of the chelating agent 2,6-bis(1-(3-hydroxypropyl)-1,2,3-triazol-4-yl)pyridine (PTD), exploited in fuel reprocessing in spent nuclear waste, has been studied by single crystal X-ray diffraction analysis in combination with an extensive DFT conformational investigation. In the solid-state, the elucidated crystal structur...

Drug delivery systems for the controlled and targeted release of drugs are in continuous development nowadays, allowing to benefit of ever better and more effective therapies. Chemical engineers thanks to their multidisciplinary preparation ranging from a thorough knowledge of transport phenomena to the transformations of matter, play a fundamental...

Pyridine-based bispidine ligands L1-L7, which differ in the substituent at the N7 position of the bispidine scaffold, have been studied by single crystal X-ray diffraction and density functional theory (DFT) calculations, also including solid-state algorithms. Qualitative description of the packing interactions and quantitative data on the stabilit...

Astrogliosis has a very dynamic response during the progression of spinal cord injury, with beneficial or detrimental effects on recovery. It is therefore important to develop strategies to target activated astrocytes and their harmful molecular mechanisms so as to promote a protective environment to counteract the progression of the secondary inju...

Ibuprofen (IBU) is a non-steroidal anti-inflammatory drug (NSAID) commonly used in the treatment of pain, fever and inflammation. However, the administration of IBU in its free carboxylic acid form is strongly dependent on its limited solubility in aqueous solution. This mandates for an increased drug concentration to reach the therapeutic window,...

Nanogels represent a pivotal class of biomaterials in the therapeutic intracellular treatment of many diseases, especially those involving the central nervous system (CNS). Their biocompatibility and synergy with the biological environment encourage their cellular uptake, releasing the curative cargo in the desired area. As a main drawback, microgl...

A process featuring a sequential multicomponent reaction followed by regioselective post-cyclization strategy was implemented for the facile synthesis of N,N’-disubstituted dihydroorotic acid amides in very mild condition. We obtained, for the first time, a library of 29 derivatives, encompassing 19 Nα-substituted-N4-dihydroorotyl-4-aminophenylalan...

The antimicrobial activity represents a cornerstone in the development of biomaterials: it is a leading request in many areas, including biology, medicine, environment and industry. Over the years, different polymeric scaffolds are proposed as solutions, based on the encapsulation of metal ions/particles, antibacterial agents or antibiotics. Howeve...

Ene reductases from the Old Yellow Enzyme (OYE) family are industrially interesting enzymes for the biocatalytic asymmetric reduction of alkenes. To access both enantiomers of the target reduced products, stereocomplementary pairs of OYE enzymes are necessary, but their natural occurrence is quite limited. A library of wild type ene reductases from...

New N‐substituted‐2‐amino‐4,5,6,7‐tetrahydrothieno[2,3‐c]pyridine derivatives were synthesized employing a convenient one‐pot three‐component method and their structures were characterized by 1H‐NMR and single crystal X‐ray diffraction analysis. All the synthesized compounds were in vitro screened for antimicrobial activity against Gram‐positive (S...

Ligands L1 and L2 have been designed, synthesized and used to build for the first time bispidine‐based coordination polymers (CPs) in combination with Mn(II). The novel CPs have been structurally characterized by SC‐ and P‐XRD techniques, showing that they are composed of 1D ribbon like chains which adopt various arrangements depending on the trapp...

The application of a number of chiral bispidine-based ligands in the copper-catalyzed enantioselective Henry reaction is here reported. The results showed good conversion rates and low to moderate enantiomeric ratios, depending on the substituents on the bispidine core. The enantioselectivities of selected ligands were rationalized on the basis of...

The use of neural stem cells (NSCs) in cell therapy has become a powerful tool used for the treatment of central nervous system diseases, including traumatic brain and spinal cord injuries. However, a significant drawback is related to the limited viability after transplantation in situ. The design of three-dimensional (3D) scaffolds that are capab...

The use of neural stem cells (NSCs) in cell therapy appears as a powerful tool for the treatment of central nervous system diseases, including traumatic brain and spinal cord injuries. However, a significant drawback is related to the limited viability after transplantation in situ. The design of three-dimensional (3D) scaffolds able to resemble th...

Peptidomimetics have raised a considerable attention in the last decades due to their potential application as therapeutic agents. In this perspective, multicomponent reactions are an excellent tool to rapidly afford a large number of drug candidates having a great structural diversity. We report here on the use of the three-component Ugi reaction...

Polymer functionalization strategies have recently attracted relevant attention for several applications in biomaterials science. In particular, technological advancements in medical imaging has focused on the design of polymeric matrices to improve non-invasive approaches and the diagnostic accuracy. In this scenario, the use of microwave irradiat...

A collection of systematically substituted 3-cyclo-butylcarbamoyl hydantoins was synthetized by a regioselective multicomponent domino process followed by easily coupling reactions. Calculations, NMR studies and X-ray analysis show that these scaffolds...

The development of nanogels as nanoscale multifunctional polymer-based matrices for controlled drug and gene delivery purposes has been the subject of intense research during the last decades. Indeed, polymeric nanoparticles are capable to interact with cells to different extents, depending on their size, shape, surface properties and ligands tagge...

One of the most important drawbacks of nanomedicine is related to the unwanted rapid diffusion of drugs loaded within nanocarriers towards the external biological environment, according to the high clearance of body fluids. Therefore, colloids can carry only a small amount of their initial content in the target district, limiting their pharmacologi...

3-Substituted oxindoles are very interesting molecules both for their potential biological activity and for their role as starting materials toward more complex oxindole-based structures. These molecules can be prepared by the reduction of a 3-ylidene oxindole precursor by classical metal-catalysed chemical reductions of the olefin. In this work we...

The synthesis of nanogels as devices capable to maintain the drug level within a desired range for a long and sustained period of time is a leading strategy in controlled drug delivery. However, with respect to the good results obtained with antibodies and peptides there are a lot of problems related to the quick and uncontrolled diffusion of small...

A family of chiral quaternary 3-aminooxindole butenolides has been synthesized by BINOL-derived phosphoric acid-catalyzed addition of trimethylsiloxyfuran to isatin-derived ketimines. Such a vinylogous Mannich-type reaction was found to produce diastereoisomeric butenolides in good yields and in most cases high enantiomeric excesses. The configurat...

A new asymmetric, Broensted acid catalyzed Biginelli-like transformation is developed and the stereochemical outcome is rationalized using computational studies on the reaction transition state.

The development of nanogels as nanoscale multifunctional polymer-based matrices for controlled drug and gene delivery purposes has been the subject of intense research during the last decades. Their use in biomedical field is related to the effect of their size on the interactions with living cells: only within a defined range nanoparticles could b...

The first asymmetric, Brønsted acid-catalyzed Biginelli-like reaction of a ketone has been developed, employing N-substituted isatins as carbonyl substrates, and urea and alkyl acetoacetates as further components. BINOL-derived phosphoric acid catalysts have been used to achieve the synthesis of a small library of chiral, enantioenriched spiro(indo...

Three chiral derivatives of the alkaloid sparteine (bispidines), characterized by the 3,7-diazabicyclo[3.3.1]nonane moiety, were designed as efficient ligands in a number of enantioselective reactions due to their metal coordination properties. A full evaluation of the 3D properties of the compounds was carried out, as the geometrical features of t...

In the last decades interests on cleavable linkers are growing due to the need to develop controlled drug delivery systems in biochemical and therapeutic applications. The synthesis of hydrogels as devices capable to maintain the drug level within a desired range for a long and sustained period of time is a leading strategy for this aim. However re...

Stem cell therapy with human mesenchymal stem cells (hMSCs) represents a promising strategy in spinal cord injury (SCI). However, both systemic and parenchymal hMSCs administrations show significant drawbacks as a limited number and viability of stem cells in situ. Biomaterials able to encapsulate and sustain hMSCs represent a viable approach to ov...

A small family of structural analogues of the antimitotic tripeptides, hemiasterlins, have been designed and synthesized as potential inhibitors of tubulin polymerization. The effectiveness of a multicomponent approach was fully demonstrated by applying complementary versions of the isocyanide-based Ugi reaction. Compounds strictly related to the l...

A series of 1,4-disubstituted piperazine-based compounds were designed, synthesized, and evaluated as dopamine D2/D3 receptor ligands. The synthesis relies on the key multicomponent split-Ugi reaction, assessing its great potential in generating chemical diversity around the piperazine core. With the aim of evaluating the effect of such diversity o...

To satisfy the increasing need for improved tissue substitutes, tissue engineering seeks to create synthetic, three-dimensional scaffolds made from polymeric materials that can carry and release cells and growth factors to induce new tissue formation. Materials science, in conjunction with biotechnology, can satisfy these needs by developing artifi...

Chiral products play an important role particularly in the field of medicinal chemistry, where it is known that enantiomers often have very different biological properties and effects. One of the most powerful tool to obtain a product as a single enantiomer is asymmetric catalysis. Recently, organocatalysis, i.e. the use of small organic molecules...

A multistep stereoselective synthesis of each stereoisomer of Nicotiana tabacum lactone is reported. A two steps reduction of an α,β-unsaturated ketoester gives the corresponding key intermediate ethyl 4-hydroxy-3-methylpentanoate. This one pot synthesis was catalyzed by a multienzymatic system comprising an ene-reductase (ER) and an alcohol dehydr...

Click chemistry reactions have recently attracted significant attention for several applications in biomaterials science. In addition microwave irradiation of aqueous solutions containing appropriate combinations of polymers is gaining increasing interests in the synthesis of sterile hydrogels without using monomers, eliminating so the need for rem...

An efficient Ugi three-component reaction of a preformed chiral ketimine derived from isatin with various isonitrile and acid components has been developed. The reactions proceeded smoothly and in a stereocontrolled manner with regard to the new center of the Ugi products due to the stereoinduction of the amine chiral residue. A wide variety of nov...

A representative series of structural analogs of the antimitotic tripeptides hemiasterlins have been designed and synthesized, as potential inhibitors of tubulin polymerization. Relying also on a computational approach, we aimed to explore unknown extensive changes at the C-fragment, by incorporating the conformationally required double bond into f...

This paper reports the synthesis of a series of evodiamine derivatives. We assayed the ability to inhibit cell growth on three human tumour cell lines (H460, MCF-7 and HepG2) and we evaluated the capacity to interfere with the catalytic activity of topoisomerase I both by the relaxation assay and the occurrence of the cleavable complex. Moreover, w...

Introduction Bioreduction of α,β-Unsaturated Carbonyl Compounds Bioreduction of Nitroolefins Bioreduction of α,β-Unsaturated Carboxylic Acids and Derivatives Bioreduction of α,β-Unsaturated Nitriles Concluding Remarks

This study reports on our ongoing investigation on hybrid EM-2 analogues, in which the great potential of β-amino acids was exploited to generate multiple conformational modifications at the key positions 3 and 4 of the parent peptide. The effect on the opioid binding affinity was evaluated, by means of ligand stimulated binding assays, which indic...

Evodiamine, a racemic quinazolinocarboline alkaloid isolated from the traditional Chinese medicine Evodiae fructus, has been reported to acts as an agonist of the transient receptor potential vanilloid type-1 (TRPV1) cation channel both in vitro and in vivo. Evodiamine is structurally different from all known TRPV1 activators, and has significant c...

A stereoselective synthesis of bicyclic primary or secondary amines, based on tetralin or chroman structural moieties, is reported. These amines are precursors of important active pharmaceutical ingredients such as rotigotine (Neupro®), robalzotan and ebalzotan. The key step is based on a multienzymatic reduction of an α,β-unsaturated aldehyde or k...

The ene-reductases mediated bioreduction of a selection of open-chain α-alkyl-β-aryl enones afforded the corresponding saturated α-chiral ketones in high yield and optical purity in several cases. The stereo-electronic requirements of the reaction have been investigated, considering the nature and location of substituents on the aromatic ring as we...

The synthesis of novel spirocyclic lactams, embodying d-tryptophan (Trp) amino acid as the central core and acting as peptidomimetics, is presented. It relies on the strategic combination of Seebach's self-reproduction of chirality chemistry and Pictet-Spengler condensation as key steps. Investigation of the conformational behavior by molecular mod...

Aiming at restricting the conformational freedom of tryptophan-containing peptide ligands, we designed a THBC (tetrahydro-β-carboline)-DKP (diketopiperazine)-based peptidomimetic scaffold capable of arranging in an unusual α-turn conformation. The synthesis is based on a diastereoselective Pictet-Spengler condensation to give the THBC core, followe...

This study reports on new pharmacologically active endomorphin-2 analogues, incorporating β 2-hPhe, β 3-hPhe and β 3-hTic unnatural amino acids in the place of the Phe3–Phe4residues. Such α, β-hybrid analogues were designed to exploit the great potential of β-amino acids in generating conformational variation at the key positions 3 and 4, with the...

We report here a two step efficient route for the synthesis of 1,2,3,4-tetrahydro-β-carboline (THBC)-based tetracyclic peptidomimetics from a Ugi 4-CR/Pictet-Spengler reaction sequence. Suitably N-protected 2-aminoacetaldehyde was for the first time applied as the carbonyl component in a Ugi four-component reaction, opening the way to the employmen...

A simple and straightforward synthesis of a tetranuclear copper(I)–pyridine–iodide cluster is described as a laboratory experiment for advanced inorganic chemistry undergraduate students. The product is used to demonstrate the fascinating and visually impressive phenomenon of luminescence thermochromism: exposed to long-wave UV light, the crystalli...

The baker’s yeast (BY)-mediated reduction of a set of α-substituted derivatives of cinnamaldehyde to give the corresponding saturated alcohols was investigated. Our study demonstrates that the ene reductases of BY (OYE 2 or OYE 3) preferentially reduce the CC double bond of stereoisomers with the phenyl group trans to the carbonyl group. Moreover,...

To overcome the usually low productivities of the C=C bond bioreduction of α,β-unsaturated aldehydes we combined the in situ substrate feeding product removal (SFPR) technology with a cascade system comprising an isolated ene-reductase and a chemoselective alcohol dehydrogenase.

The coupling of the enantioselective reduction catalyzed by Old Yellow Enzymes (OYEs), together with the in situ substrate feeding product removal (SFPR) concept, significantly improved the productivity of the g-scale preparation of ethyl (S)-2ethoxy-3-(p-methoxyphenyl)propanoate (EEHP), an important precursor of several PPAR-alpha/gamma agonists,...

We investigated the Strecker-type reaction of isatin derived chiral ketimines with TMSCN in the presence of a Lewis acid. The desired α-amino nitriles have been obtained in good yields with moderate diastereoselectivity. Further elaboration of the cyanide group allowed the preparation of a new oxindole-based peptidomimetic and a pharmaceutically re...

The oxidation of 3-heteroarylindoles to the corresponding oxindoles with t-butyl hypochlorite has been investigated. Under carefully adjusted conditions, preparative scale of desired products can be achieved. Two competing pathways seem to contribute to the reaction mechanism, affording 3-heteroaryloxindoles bearing hydrogen or chlorine at C3, depe...

The synthesis of a novel Phe-Ala dipeptide mimic, built up on a diazaspirocyclic lactam core, is presented. This new scaffold was evaluated for conformational mimicry of reverse turn by combining molecular modeling, IR, NMR, and X-ray diffraction experiments. All these tools agree on the presence of a strong intramolecular hydrogen bond, thus demon...

A concise asymmetric total synthesis of the potentially bioactive 275A lehmizidine frog skin alkaloid (or of its enantiomer) is described. Key features of the protocol include an acyliminium butenyl Grignard addition and a seven-membered intramolecular reductive amination step. Both reactions ensure a high degree of diastereocontrol, with installat...

The results of our studies on the biocatalytic enantioselective synthesis of different 3-aryl-2-nitropropanols are presented. These compounds could be obtained in moderate to good ee both by baker's yeast mediated reduction of (E)-2-nitro-3-arylprop-2-en-1-ol precursors and by lipase kinetic resolution of racemic 3-aryl-2-nitropropanols. The synthe...

An unprecedented chiral spiropiperidine oxindole system was synthesized starting from enantiopure quaternary 3-aminooxindole and relying on a ring closing metathesis as the key step. This compound acts as an highly constrained Freidinger γ-lactam, adopting a type II β-turn conformation in solution, as assessed by modelling and spectroscopical studi...

We present here spirocyclic lactam derivatives, embodying D-Phe and L-Ala amino acids as the central core and acting as tetrapeptide and hexapeptide mimetics. An efficient route for their synthesis is demonstrated by using the strategic combination of Seebach's self-reproduction of chirality chemistry and the Pictet-Spengler condensation as key ste...