Bassam El Ali

King Fahd University of Petroleum and Minerals | KFUPM · Department of Chemistry

This work describes the first report of the known glycosidic constituents β-sitosterol-3-O-β-d-glucoside-6'-palmitate (1), β-sitosterol-3-O-β-d-glucoside (2), momor-cerebroside I (3), phytolacca cerebroside (4), 1,2-di-O-palmitoyl-3-O-(6-sulfoquinovopyranosyl)-glycerol (5), isorhamnetin-3-robinobioside (6), and isorhamnetin-3-rutinoside (7) from th...

In this study, a novel hybrid sol-gel coating on AA3003 substrate was developed and the effects of various waste material additives on the reinforcement of the sol-gel coating and the anticorrosion properties in the saline medium were investigated. Egg shell, crumb rubber, activated carbon obtained for pyrolysis of waste rubber tire, waste rubber t...

The N-heterocyclic carbene (NHC) iridium(I) complex [IrCl (COD)(IMes)] [IMes=1,3-bis(2,4,6-trimethylphenyl) imidazole-2-ylidene] showed an excellent catalytic activity in the reactions of the aerobic oxidative coupling of thiols into disulfides. The use of oxygen of air as a green oxidant allows the thiols to be quantitatively converted into the co...

Biaryl ketones and biaryl diketones have utility as synthetic intermediates, particularly for the synthesis of heterocyclic systems that can be used as precursors in the synthesis of dyes and liquid crystals for electronic displays. Biaryl ketones and biaryl diketones have also found use in the polymer industry. A common route for the synthesis of...

The phytochemical analysis of the butanolic extract from the leaves of date palm of Saudi origin resulted in the isolation of three major constituents, oleanolic acid (1), vanillyl alcohol (2), and β-sitosterol-3-O-β-d-glucoside (3), which had not been isolated from this plant or previously reported. Together, compounds 1 and 2 account for 1.0% of...

A series of three 1,3-propanediyl bridged bis(N-heterocyclic carbene)palladium(II) complexes (Pd-BNH1, Pd-BNH2, and Pd-BNH3), with +I effect order of the N-substituents of the ligand (isopropyl > benzyl > methoxyphenyl), was the subject of a spectroscopic, structural, computational and catalytic investigation. The bis(NHC)PdBr2 complexes were evalu...

Abstract Highly active and efficient propylene‐bridged bis(N‐heterocyclic carbene)palladium(II) complexes covalently anchored on Merrifield's resin were synthesized and characterized using various physical and spectroscopic techniques. The two anchored Pd(II) complexes consist of the system: Merrifield's resin‐linker‐bis(NHC)Pd(II), the linkers bei...

The one-pot regioselective and catalytic synthesis of bioactive chromones and flavones was achieved via phosphine-free cyclocarbonylative Sonogashira coupling reactions of 2-iodophenols with aryl alkynes, alkyl alkynes, and dialkynes. The reactions are catalyzed by new dibromidobis(NHC)palladium(II) complexes. The new bridged N,N′-substituted benzi...

N,N′-Substituted di-isopropyl (NHC-1), benzyl-isopropyl (NHC-2), and adamantyl-isopropyl (NHC-3) benzimidazolium salts react with palladium(II) bromide in pyridine to afford the corresponding trans-dibromidopyridinepalladium(II) complexes Pd-C1, Pd-C2, and Pd-C3 in high yields. A distorted square planar geometry for Pd-C2 and Pd-C3 was confirmed by...

Bridged N,N′‐substituted bisbenzimidazolium bromide salts (L1, L2, and L3) were synthesized and fully characterized. Reactions of palladium acetate with L1, L2, and L3 afforded corresponding new bridged bis(N‐heterocyclic carbene)palladium(II) complexes (C1, C2, and C3) in high yields. The X‐ray structure of complex C1 showed that the Pd(II) ion is...

Hybrid sol–gel materials have been found very promising anticorrosive coatings for metal substrates. In this article, the synthesis of novel hybrid organic‐inorganic sol–gel polymer; starting from tetraethyl orthosilicate, (3‐aminopropyl) trimethoxysilane, dimethoxy‐methyl‐octadecylsilane and polydimethylsiloxane, silanol terminated precursors, is...

New N,N′-substituted imidazolium salts and their corresponding dibromidopyridine–palladium(II) complexes were successfully synthesized and characterized. Reactions of palladium bromide with the newly synthesized N,N′-substituted imidazolium bromides (2a and 2b) in pyridine afforded the corresponding new N-heterocyclic carbene pyridine palladium(II)...

New N, N′-substituted imidazolium salts (L1 and L2) and their corresponding diiodopyridinepalladium(II) complexes (C1 and C2) were successfully synthesized and characterized. Reactions of palladium iodide with the newly synthesized N, N′-substituted imidazolium iodides in pyridine afforded the corresponding new palladium-N-heterocyclic carbene pyri...

The catalytic activity and the recycling ability of palladium–bis(oxazoline) (Pd–BOX-M) complex supported on Merrifield’s resin have been investigated in Suzuki–Miyaura and Mizoroki–Heck cross-coupling reactions of aryl bromides and aryl chlorides. The supported palladium–bis(oxazoline) catalyst demonstrated exceptional catalytic activity and excel...

This work assessed the anticorrosion and antifouling properties of a novel sol-gel derived hybrid coating functionalized with 5 different organic and inorganic biocides. FTIR and NMR analysis of the newly synthesized polymeric base material confirmed the photo-induced organic polymerization of the allyl groups in the allyltrimethoxysilane precursor...

New amido-amine-based cationic gemini surfactants with flexible and rigid spacers and different hydrophobic tails were synthesized and characterized. These gemini surfactants were prepared by modified procedure through amidation of long chain carboxylic acids using 3-(dimethylamino)-1-propylamine followed by treatment with halohydrocarbons. The eff...

A palladium(II)-bis(oxazoline) complex supported on silica (Pd-BOX-Si) was prepared, characterized and applied as a catalyst in Mizoroki–Heck cross-coupling reactions. The bis(oxazoline) (BOX) ligand has a hydroxyl group that can be anchored to 4-benzyl chloride-functionalized silica gel, followed by the coordination of palladium(II) chloride. The...

The encapsulation of corrosion inhibitors in sol–gel coatings is a practical method for protecting mild steel against corrosion. Another recent approach involves the localization of a biologically active reagent close to the metal substrate. In this study, we have utilized the above two approaches in developing bacteria and inhibitor-doped sol–gel...

The catalytic synthesis of aryl esters and amides has been successfully achieved in the presence of the efficient palladium-bisoxazoline supported on Merrifield's resin (Pd-BOX-M). The palladium heterogeneous catalyst was prepared and characterized using various spectroscopic techniques. A bisoxazoline ligand having a suitable functional group (BOX...

A copper- and phosphine-free Sonogashira cross-coupling of aryl iodides with terminal alkynes under aerobic conditions is presented.

New cationic palladium-bis(oxazoline)-phosphine (Pd-BOX-PR3) complexes (Pd-BOX-B and Pd-BOX-C) have been synthesized and characterized using 1H, 13C and 31P NMR, FT-IR spectroscopy and electrospray ionization mass spectrometry (ESI-MS). The new complexes were used as catalysts in the alkoxycarbonylation of alkynes with various alcohols as nucleophi...

The growth of some bacterial biofilms have been widely reported to have defined consequences on industrial metals, and their related metabolic activities affect the overall electrochemical process of these metals in any given medium. This work seeks to unravel the role of thermophilic Bacillus licheniformis biofilm (an isolate from the Jazan spring...

The reaction mechanisms of the palladium-catalyzed alkoxycarbonylation of α,β-unsaturated amides are studied by means of density functional theory (DFT) at the B3LYP/def2-TZVP//B3LYP/def2-SVP level of theory including solvent and dispersion corrections. Two possible pathways, hydride and alkoxy, are examined and their corresponding intermediates an...

New bis(oxazoline) ligands and their palladium complexes were synthesized and characterized. X-ray crystal structures of the two new complexes showed distorted square planar geometry with the palladium ion bonded to nitrogens of two bidentate heterocycles in addition to two bromides and two acetate ions for Pd-BOX-1 and Pd-BOX-2, respectively. The...

A highly efficient protocol for the copper and phosphine free Sonogashira cross-coupling reactions of aryl iodides with terminal alkynes under aerobic conditions has been developed. Using 1 mol % of the palladium-bis(oxazoline) complex, Pd-BOX A, in the presence of KOH, and a CH3CN–H2O solvent system allowed for the cross-coupling reactions to proc...

This work reports the performance of a sol-gel type coating encapsulated with biofilm of inoculums of protective thermophilic strain of Bacillus licheniformis endospores isolated from the Gazan hot springs-Saudi Arabia for the inhibition of marine fouling and corrosion protection of S36-grade mild steel in 3.5 wt% NaCl medium. In order to improve i...

An efficient catalytic system for the title cross coupling reactions based on a novel palladium-bis(oxazoline) complex is developed which exhibits exceptional air and moisture stability.

An efficient catalytic system based on a new palladium–bis(oxazoline) (Pd-BOX-1) complex has been developed. The complex Pd-BOX-1 adopts a legless chair‐type structure where the distorted square planar [PdN2Cl2] moiety and the benzene ring spacer represent the seat and the chair back, respectively. The catalytic activity of Pd-BOX-1 has been invest...

Novel hybrid-sol-gel materials (C1-C5) based on silica-epoxy composite resins were successfully prepared by coupling different aminosilanes with DER736 epoxy resin, followed by in situ sol-gel process, and finally introducing the urethane moieties to the final coatings. The research has emphasized on the effect of changing the type of the aminosila...

A new series of bimetallic bis(diphenylphosphino)acetylene-bridged copper(I) 1,10-phenanthroline complexes, [Cu-2(dppa)(2)(L)(2)](BF4)(2); L = 1,10-phenanthroline (1); 4-methyl-1,10-phenanthroline (2); 4,7-dimethyl-1,10-phenanthroline (3); and 2,9-dimethyl-1,10-phenanthroline (4), have been prepared and characterized by spectroscopic methods. The X...

Corrosion inhibition potentials of two imidazole derivatives namely, vinylimidazole (VI) and allylimidazole (AI) for carbon steel in 1 M HCl at 25 °C were predicted theoretically using quantum chemical calculations and molecular dynamics (MD) simulations. DFT calculations indicated that VI is more reactive towards steel surface than AI. Equilibruim...

Current legislation around the use of antifouling and anticorrosion coatings has increased the need to find an environment friendly alternative to existing biocide containing pretreatments for steel structures exposed to sea water. Sol-gel technology offers a solution to fouling and corrosion inhibition since sol-gel chemistry lends itself ideally...

Hydroformylation of olefins is versatile method and well-established industrial process for the production of aldehydes using transition metal complexes as homogeneous catalysts. For any industrial application of homogeneously catalyzed process requires an efficient combination of both a high-yield reaction and efficient catalyst recycling. Rhodium...

New palladium–bis(oxazoline) (Pd–BOX) complexes were synthesized and characterized. The X-ray crystal structures of the two complexes showed that the palladium ion is bound to the nitrogen atoms of the two heterocycles of the bidentate ligand and two chloride ions in a distorted square planar geometry. The coordination to the palladium ion allows t...

New hybrid organic–inorganic coatings have been developed by reacting a mixture of 3-glycidoxypropyltrimethoxysilane (GPTMS) and tetraorthosilicate (TEOS) with 2–4% aminoethylaminopropyl-methylsiloxane dimethylsiloxane (APDMS) copolymer as a modifier. The sol–gel polymerisation of the inorganic components was achieved by base catalysation using NaO...

A batch-wise flow system for the determination of chloride in drinking water is described. For the first time, a sequential injection analysis performed using a programmable syringe pump is used to replace the sequential injection instrument. Direct current differential electrolytic potentiometry was applied as a detector. The heights of the result...

Four new bis(diphenylphosphino)acetylene-bridged copper(I) bipyridine complexes, [Cu2(dppa)2(L)2](BF4)2; L = 2,2′-bipyridine (1), 4,4′-dimethyl-2,2′-bipyridine (2), 5,5′-dimethyl-2,2′-bipyridine (3) and 6,6′-dimethyl-2,2′-bipyridine (4), have been prepared and characterized by spectroscopic methods. X-ray crystal structure analyses of complexes 2-4...

New conjugated dienamides have been synthesized effectively via palladium-catalyzed aminocarbonylation of enynes in the presence of various amines, diaminoalkanes, and aminoalcohols. The products have been utilized as substrates in alkoxycarbonylation reactions using methanol as the nucleophile and Pd(PPh3)2Cl2 as the catalyst to afford novel ω-ami...

A series of new binuclear Pd(II) complexes based on chelating diimines and bridging diphosphine or diimine ligands have been synthesized and characterized successfully. The formula of the new complexes are [Pd2(mbyp)2(DPA)2](PF6)4 (1), [Pd2(mbyp)2(DPE)2] (PF6)4 (2), [Pd2(mbyp)2(4,4-byp)2] (PF6)4 (3), [Pd2(mbyp)2(t-pye)2] (PF6)4 (4) [mbyp = 4,4’-dim...

Ultranox626 as a diphosphite ligand showed high selectivity and good yields when used with Rh(CO)2(acac) as a catalyst precursor in the hydroformylation of allylbenzene derivatives producing aldehydes, and also in the one-pot hydroformylation–acetalization forming acetals. These reactions proceed smoothly and effectively to produce the linear aldeh...

A DFT study on the palladium-bisphosphine catalyzed alkoxycarbonylation and aminocarbonylation of alkyne (propyne) is reported. The theoretical study explores the feasibility and the regioselectivity control of two independent mechanisms: the first is based on the active intermediate [Pd(II)(P(2))(H)](+) (where P(2) = PH(2)CH(2)CH(2)CH(2)CH(2)PH(2)...

The alkoxycarbonylation of alpha,beta-unsaturated amides proceeded efficiently and regioselectivity to give omega-amido esters with complete conversion in the presence of the catalyst system: Pd(PPh(3))(2)Cl(2)/MeOH/CO/H(2)O. The reaction was successfully applied to the alkoxycarbonylation of bis-acrylamides yielding, selectively, the corresponding...

A variety of 5-, 6-, and 7-membered ring lactones and lactams have become available via carbonylative cyclization reactions catalyzed by different transition metal complexes. Palladium and rhodium complexes are the most widely used catalysts for the cyclization reactions. Furanones can be synthesized either by the catalytic intermolecular cyclocarb...

The one-pot hydroformylation–cyclization of allylbenzene derivatives by the catalyst system Rh(CO)2acac/ultranox626/CO/H2/CH2Cl2 led chemoselectively to 5,6-dihydronaphthalene derivatives 5a–d in good yields. The addition of a catalytic amount of H3PO4 enhanced in situ the cyclization process via the nucleophilic attack on the carbonyl group of the...

Di-, and trisubstituted 1,3-dienes are converted to γ,δ-unsaturated acids by use of formic acid, carbon monoxide, and catalytic quantities of PdC / PPh3 / Ph2P(CH2)4PPh2 in 1,2-dimethoxyethane. A β,γ-unsaturated acid was obtained when the monosubstituted diene, isoprene, was used as the reactant.

New copper(I) mixed-ligand complexes 1–4 of the formula Cu(N–N)PR3X, where N–N=1,10-phenanthroline (phen), 2,2′-bipyridine (bpy), 5,5′-dimethyl-2,2′-bipyridine (5,5′dimbpy) and PR3=tricyclohexylphosphine, tris(2-cyanoethyl)phosphine and isopropyldiphenylphosphine, have been synthesized. The complexes were characterized by EA, IR, NMR and single cry...

The aminocarbonylation and alkoxycarbonylation reactions of terminal alkynes took place smoothly and efficiently using a catalyst system Pd(OAc)2–dppb–p-TsOHCH3CNCO under relatively mild experimental conditions. The catalytic system was tested and optimized using two different nucleophiles: alcohols and amines. Phenylacetylene (1a) was considered a...

The regioselective alkoxycarbonylation of phenylacetylene into various cinnamate esters was achieved with a catalyst system formed from palladium (II), 1,4-bis(diphenylphosphino) butane (dppb) and salicylborate complex in acetonitrile as a solvent. The influence of various parameters on the overall conversion of phenylacetylene and the selectivity...

IntroductionIntermolecular Hydrocarboxylation and Hydroesterification of Unsaturated SubstratesIntramolecular Cyclocarbonylation of Unsaturated CompoundsConclusion References

The corrosion properties of steel have been studied in acidic solution containing polymeric inhibitors. 2-Phosphonobutane-1,2,4 tricarboxylic acid (PBTCA) was used as a corrosion inhibitor for carbon steel in cooling water either alone or in combination with polyvinylpyrrolidone (PVP). The inhibiting properties of those compounds were investigated...

The structural stability of sulfolane (tetrahydrothiophene1,1-dioxide) and 3-sulfolene (dihydrothiophene1,1-dioxide) was investigated by DFT-B3LYP and ab initio MP2 calculations with 6-311+G**) basis set. The calculated symmetric ring-puckering potential of 3-sulfolene at the B3LYP level is consistent with a flat minimum that corresponds to a plana...

Novel cationic mixed-ligand palladium and platinum complexes based on the chelating ligands 4,7-dimethyl-1,10-phenanthroline and 2,2 0 -bipyridine with a pyridine bearing the nitronylnitroxide radical are reported. The synthesis, X-ray crystal structures and magnetic properties of the two complexes [Pd(4,7-dimethyl-1,10-phenanthroline)(NIT-pPy) 2 ]...

Rhodium (I) associated with [bis(2,4-di-tert-butyl) pentaerythritol] diphosphite (I) as a ligand represents an active catalyst system for highly regioselective hydroformylation of various alkenes. The commercially available bis(2,4-di-tert-butyl)pentaerythritol diphosphite (alkanox P-24) (I), which has been used so far as an antioxidant in the stab...

Desulphurization of FCC gasoline and diesel fuels has been investigated by chemical oxidation of sulphur containing compounds with hydrogen peroxide in the presence of an acid catalyst such as formic acid and acetic acid, followed by extraction of the oxidized compounds using acetonitrile. Oxidative desulphurization (ODS) of diesel fuel was found t...

Heteropolyacids impregnated with rhodium(I) or (III) complexes were prepared and used as supported catalysts in the hydroformylation of alkyl alkenes. Two general types of catalysts were prepared and tested: rhodium(I) or (III) in the presence and in the absence of the heteropolyacid H3PW12O40, 25H2O (adopted as HPW12) supported on MCM-41 (30Å). 1-...

A thermomorphic approach to rhodium-catalyzed biphasic hydroformylation of higher olefins (C > 6) has been developed based on HRhCO(PPh3)3/P(OPh)3/propylene carbonate/n-heptane catalytic system. The catalyst system showed excellent selectivity toward the desired linear aldehyde (n/i ratio > 8) and high catalytic activity demonstrated by the efficie...

Rh(I) and Rh(III) impregnated on mesoporous supports such as MCM-41 have demonstrated a very high catalytic activity in the production of acetals under the hydroformylation conditions of alkenes. The one pot process that combines hydroformylation and acetalization processes leading to acetals as major products was carefully studied. R(I) supported...

Rh supported catalysts were prepared by impregnating rhodium(I) and rhodium(III) complexes with and without heteropolyacids for the hydroformylation of styrene derivatives. The effect of the pore size of MCM-41 was considered. The addition of water showed a promoting effect with Rh(III) based catalysts. The amount of water showed also a big effect...

Acetals were formed under hydroformylation conditions of alkenes in alcohols as solvents. The hydroformylation process is combined with acetalization in a one-pot reaction leading to acetals as final products. These reactions sequences were catalyzed by the simple rhodium catalyst RhCl(3)center dot 3H(2)O. The effects of the addition of different t...

Active homogeneous catalytic systems based on Rh6(CO)16-heteropolyacids for the regioselective hydroformylation of styrene and 1-octene and their derivatives have been developed. The effects of the amount and the type of the heteropolyacid have been studied and showed a significant improvement of the conversion of styrene and the selectivity toward...

The heterogeneous hydroformylation reaction represents an attractive industrial route for the production of aldehydes due to the relatively easy separation of products and high turnover of the rhodium catalysts. To study the recycling process and the characterization of the supported catalyst, a catalyst was prepared by impregnating 5% of HRhCO(PPh...

The reaction of carbonylative addition of alkyl alkynes to aniline derivatives has been successfully achieved by a catalytic system formed of Pd(OAc)2 and a suitable bidentate phosphine ligand. The reaction led mainly to gem-α,β-unsaturated amides (3) with Pd(OAc)2/1,3-bis(diphenylphosphino)propane/p-toluenesulfonic acid/CO as the catalytic system....

A new catalytic system formed of RhCl3, 3H2O as a catalyst and triethyl orthoformate, HC(OEt)3, as a solvent showed high catalytic activity in the reaction of hydroformylation of aryl, terminal and internal alkyl alkenes, and also cycloalkenes. The addition of the triphenyl phosphite, P(OPh)3, increased the selectivity toward the branched aldehydes...

The combination of palladium acetate and 1,4-bis(diphenylphosphino)butane (dppb) proved once again to form an effective catalytic system for the selective cyclocarbonylation of 2-allyl phenols and other bis-2-allyl phenol systems such as steroids and other important compounds. The reactions afforded new important five-, six- and seven-membered ring...

A new one pot reaction of hydroformylation–cyclotrimerization of cyclopentene 1a and cyclohexene 1b was selectively catalyzed by Rh6(CO)16 and H3PW12O40·xH2O (HPA-W12) in THF as a solvent at 40 atm (CO/H2=1/1) to give 2,4,6-trisubstituted-1,3,5-trioxanes 3a and 3b as major products along with the corresponding aldehydes 2a and 2b.

Pd-catalyzed carbonylation of aryl, vinyl, and benzyl halides and pseudo aryl or vinyl halides is described. The authors give special focus to the intermolecular acylpalladation of π-bond systems and its related chemistry. Several unique features associated with the reactions of acylpalladium derivatives derivable from allyl-, propargyl-, and allen...

Two new complexes [Pt(IM2Py)Cl2] and [Pd(IM2Py)Cl2] revealed structural phase transitions from pseudo-orthorhombic to monoclinic systems. Despite the two compounds remaining isostructural, the magnetic properties revealed dominant ferromagnetic interactions for the Pt derivative, whereas antiferromagnetic interactions take place for the Pd compound...

Palladium acetate [Pd(OAc)2] and 1,4-bis(diphenylphosphino)butane (dppb) catalyse cyclocarbonylation of allylic cardanol and cardol derivatives to give regioselectively 7-membered ring lactones in good yields. One of the compounds prepared exhibits excellent antioxidant properties.

The hydrocarboxylation and the hydroesterification of styrene was studied in the presence of PdCl2(PPh3)2 as a catalyst. The effect of the addition of the heteropolyacids of a general formula H3+nPMo12-nVnO40 (HPA-n, n=1-4) on the hydrocarboxylation and the hydroesterification of styrene was considered.

The carbonylative coupling of 1-heptyne (1a) with aniline (2a) has been successfully achieved in the presence of Pd(OAc)2 and a suitable bidentate phosphine ligand and solvent. The gem-α,β-unsaturated amide (3aa) was formed as a predominant product in the presence of the catalytic system Pd(OAc)2/1,3-bis(diphenylphosphino)propane (dppp)/p-toluenesu...

The inter- and intra-molecular regioselective cyclocarbonylative coupling of 2-aminophenol (1a) and 2-aminothiophenol (1b) with various allylhalides was achieved in the presence of a catalytic amount of palladium acetate and 1,4-bis(diphenylphosphino)butane to afford N-aryl-2-pyrrolidinones (3, 4) in 47–65% yields. Other aminophenol derivatives hav...

Four new mononuclear complexes of formula Cd(PN)(4)(NCS)(2) (A), Cd(PNN)(4)(N(3))(2) (B), Zn(PNN)(4)(N(3))(2) (C), and Zn(PNN)(2)(NCS)(2) (D), where PNN stands for 2-(4-pyridyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide and PN for 2-(4-pyridyl)-4,4,5,5-tetramethylimidazoline-1-oxyl, were synthesized and structurally and magnetically characteriz...

A series of new N-aryl-α,β-disubstituted amides (gem or E1; trans or E2) were synthesized in good yields by carbonylative addition of aniline derivatives 1a–f to aromatic alkynes 2a,b catalyzed by Pd(OAc)2 and 1,3-bis(diphenylphosphino)propane. The catalytic synthesis of tertiary α,β-unsaturated amides was also successfully achieved. Traces of prod...

The hydrocarboxylation of styrene has been carried out in the presence of PdCl2(PPh3)(2) as catalyst and the heteropolyacids of general formula H3+nPMo12-nVnO40 (HPA-n, n = 1-4) as co-catalyst in THF as solvent. The heteropolyacid H5PMO10V2O40 and HCl enhanced the catalytic reaction at 80 degreesC leading to excellent selectivity of branched aldehy...

Palladium(II) regioselectively catalyzes the hydroesterification of terminal alkynes under syngas forming alpha,beta -unsaturated esters 3 and 4 in excellent chemical yields under neutral conditions. The high selectivity for the linear ester 4 was obtained with a catalytic system that includes Pd(II), 1,4-bis(diphenylphosphino)butane (dppb) and CO/...