Cintia Virumbrales

Universidad de Burgos | UBU · Department of Chemistry

A gold(I)-catalyzed cascade reaction for the stereoselective synthesis of sulfur- or selenium-containing indeno[1,2-b]chromene derivatives from o-(alkynyl)styrenes substituted at the triple bond with a thio- or seleno-aryl group is described. The reaction involves a double cyclization process through a proposed key gold-cyclopropyl carbene intermed...

A straightforward and transition metal-free one-pot protocol to synthesize halobenzo[b]furans has been developed employing simple and easily available starting materials such as O-aryl carbamates and alkynylsulfones. The fine-tuning of the different steps involved was key to achieving a successful one-pot procedure. Initially, a directed ortho-lith...

α-Oxyketones, easily accessible by conventional routes, can be selectively deprotonated generating an enolate intermediate, which upon treatment with paraformaldehyde undergoes an aldol-Tishchenko reaction, leading to relevant 1,2,3-triol fragments in a totally diastereoselective manner. The excellent stereocontrol in the generation of a quaternary...

The first general regio‐ and stereoselective 5‐exo gold(I)‐catalyzed alkoxycyclization of a specific class of 1,5‐enynes such as 1,3‐dien‐5‐ynes has been described, despite 1,5‐enynes being known to almost invariably proceed via endo cyclizations under gold‐catalysis. The configuration of the terminal alkene in the starting 1,3‐dien‐5‐yne plays a c...

The stereospecific gold(I)-catalyzed nucleophilic cyclization of β-monosubsituted o-(alkynyl)styrenes to produce C-1 functionalized 1H-indenes including challenging substrates and nucleophiles, such as β-(cyclo)alkyl-subsituted o-(alkynyl)styrenes and a variety of alcohols as well as selected electron-rich aromatics, is reported. DFT calculations s...

The synthesis of aromatic amines is of utmost importance in a wide range of chemical contexts. We report a direct amination of boronic acids with nitro compounds to yield (hetero)aryl amines. The novel combination of a dioxomolybdenum(VI) catalyst and triphenylphosphine as inexpensive reductant has revealed to be decisive to achieve this new C‐N co...

The synthesis of aromatic amines is of utmost importance in a wide range of chemical contexts. We report a direct amination of boronic acids with nitro compounds to yield (hetero)aryl amines. The novel combination of a dioxomolybdenum(VI) catalyst and triphenylphosphine as inexpensive reductant has revealed to be decisive to achieve this new C‐N co...

The cross-coupling reaction of alkenyl bromides with thiols catalyzed by palladium complexes derived from inexpensive dppf ligand is reported. These reactions occur under low catalyst loading and in high yields and display wide scope, including the coupling of bulky thiols and trisubstituted bromoolefins, and functional group tolerance. In addition...

The gold(I)-catalyzed oxycyclization of β-aryl monosubstituted o-(alkynyl)styrenes gives rise to 1-α-methoxy or 1-α-hydroxybenzyl-1H-indenes in a diastereospecific way. In contrast with β,β-disubstitued o-(alkynyl)styrenes, the stereochemical outcome of the process, diastereospecific reactions,...

Depending on the reaction temperature the title reaction affords either dihydroindeno[2,1-a]indenes (80°C) or benzofulvenes (0°C) in high yields.

Gold(I)-catalyzed cycloisomerization of β,β-diaryl-o-(alkynyl)styrenes at 80 °C selectively yields dihydroindeno[2,1-a]indenes in a transformation that encompasses a formal [4 + 1] cycloaddition and takes place through a cascade 5-endo-cyclization-diene activation-iso-Nazarov cyclization. In addition, by performing the reaction at 0 °C, the same su...