Reductive Transamination of Pyridinium Salts to N-Aryl Piperidines.

Saturated N-heterocycles are found in numerous bioactive natural products and are prevalent in pharmaceuticals and agrochemicals. While there are many methods for their synthesis, each has its limitations, such as scope and functional group tolerance. Herein, we describe a rhodium-catalyzed transfer hydrogenation of pyridinium salts to access N-(hetero)aryl piperidines.

Recent developments in enantio- and diastereoselective hydrogenation of N-heteroaromatic compounds.

The enantioselective and diastereoselective hydrogenation of N-heteroaromatic compounds is an efficient strategy to access chirally enriched cyclic heterocycles, which often possess highly bio-active properties. This strategy, however, has only been established in recent times. This is in part due to the challenges of the high stability of the aromatic compounds and the presence of heteroatoms that have the potential to poison the chiral catalysts.

Modular Construction of Protected 1,2/1,3-Diols, -Amino Alcohols, and -Diamines via Catalytic Asymmetric Dehydrative Allylation: An Application to Synthesis of Sphingosine.

A new enantioselective catalysis has been developed for the one-step construction of methylene-bridged chiral modules of 1,2- and 1,3-OH and/or NH function(s) from δ- or λ-OH/NHBoc-substituted allylic alcohols and "HC═O"/"HC═NBoc". A protonic nucleophile, either in situ-generated CHOH or CHNHBoc, is intramolecularly allylated to furnish eight possible 1,2- or 1,3-O,O, -O,N, -N,O, and -N,N chiral modules equipped with an ethenyl group in high yields and enantioselectivities. The utility of this method has been demonstrated in the five-step synthesis of sphingosine.

Tuning the Electronic Properties of 2-Cyano-3-phenylacrylamide Derivatives.

We are the first to report the synthesis of a new class of 2-cyanoarylacrylamide (2-CAA) derivatives and observe that the synthesized 2-CAA shows fluorescence properties due to the formation of a dimeric interaction of hydrogen bonds between carbonyl oxygens and amide hydrogens (C═O···H-N-C═O···H-N···); i.e., dimers are linked through dimeric N-H···O hydrogen bonds.

Efficient iodine catalyzed three components domino reaction for the synthesis of 1-((phenylthio)(phenyl)methyl)pyrrolidin-2-one derivatives possessing anticancer activities.

A simple and efficient three components domino reaction of γ-butyrolactam (2-pyrrolidinone), aromatic aldehyde and substituted thiophenol catalyzed by elemental iodine resulted in the formation of 1-((phenylthio)(phenyl)methyl)pyrrolidin-2-one derivatives. The stability of the synthesized analogues was evaluated in stimulated gastric fluid (SGF) and bovine serum albumin (BSA). In vitro anticancer activity was investigated in the low micromolar range and a few analogues were found to possess good activity.