Identification and structure-activity relationships for a series of N, N-disubstituted 2-aminobenzothiazoles as potent inhibitors of S. aureus.

An internal collection of commercial and synthetically derived small molecule compounds was screened against several drug-resistant bacterial pathogens. Compound 1, a known N, N-disubstituted 2-aminobenzothiazole, was found to be a potent inhibitor of Staphylococcus aureus and several associated clinically relevant strains of methicillin-resistant S. aureus suggesting a possible novel mechanism of inhibition.

Synthesis of Spirooxindoles via the tert-Amino Effect.

A new method is developed for the synthesis of spirooxindoles from amines and isatins via C-H functionalization. The reaction leverages the tert-amino effect to form an enolate-iminium intermediate via [1,5]-hydride shift followed by cyclization. Interestingly the hydride migrates to the N atom of a C═N, which is atypical for hydride additions to imines.

Metal- and O-Free Oxidative C-C Bond Cleavage of Aromatic Aldehydes.

An oxidative C-C cleavage of aldehydes requiring neither metals nor O was discovered. Homobenzylic aldehydes and α-substituted homobenzylic aldehydes were cleaved to benzylic aldehydes and ketones, respectively, using nitrosobenzene as an oxidant. This reaction is chemoselective for aromatic aldehydes, as an aliphatic aldehyde was unreactive under these conditions, and other reactive functionality such as ketones and free alcohols are tolerated.

Retro-Claisen benzylation: direct use of benzyl alcohols in Pd-catalyzed couplings with nitriles.

A new strategy has been developed for the benzylation of nitriles directly from benzyl alcohols. In this process benzyl alcohols undergo retro-Claisen activation with cyanoacetic esters to generate an active electrophile and a carbanionic nucleophile. In the presence of Pd(0) these intermediates undergo catalytic coupling to generate a new C-C bond, resulting in the formation of phenyl propionitriles.

Synthesis of N-aryl-1-aminoindoles via intermolecular redox amination.

A redox amination strategy was developed for the synthesis of N-aryl-1-aminoindoles by N-N bond formation. Reaction of nitrosobenzenes with readily available indolines using Brønsted acid catalysis allows N-N bond formation under mild conditions. This method exploits the inherent reducing power of indoline to synthesize biologically relevant molecular architectures via redox amination.

Sequential one-pot combination of multireactions through multicatalysis: a general approach to rapid assembly of functionalized push-pull olefins, phenols, and 2-methyl-2H-chromenes.

A general, sustainable and practical process for the sequential cascade one-pot synthesis of library of highly substituted push-pull olefins, phenols and 2-methyl-2H-chromenes was reported through multicatalysis cascade (MCC) reactions. Direct sequential one-pot combination of amine- or amino acid-catalyzed cascade Knoevenagel/Michael/aldol condensation/decarboxylation with other reactions like amine- or amino acid-catalyzed cascade Claisen-Schmidt/iso-aromatization, Claisen-Schmidt/isomerization, Claisen-Schmidt/iso-aromatization/isomerization, Michael addition, Claisen-Schmidt/Michael, ruthenium-base-silica-catalyzed ring closing metathesis/base-induced ring-opening/benzylic oxidation/[1,7]-sigmatropic hydrogen shift, or ruthenium-base-heat-catalyzed ring closing metathesis/base-induced ring-opening/[1,7]-sigmatropic hydrogen shift reactions of alkyl acetoacetates, a variety of aldehydes and alkyl halides furnished the highly functionalized push-pull olefins, phenols and 2-methyl-2H-chromenes with high yields. The yields and regioselectivities were good to excellent.

High-yielding synthesis of Nefopam analogues (functionalized benzoxazocines) by sequential one-pot cascade operations.

An efficient amine-/ruthenium-catalyzed three-step process for the synthesis of Nefopam analogues was achieved through combinations of cascade enamine amination/iso-aromatization/allylation and diene or enyne metathesis as key steps starting from functionalized Hagemann's esters. In this communication, we discovered the application of ruthenium-catalysis on olefins containing free amines without in situ formation of salts.

Organocatalytic cascade reactions based on push-pull dienamine platform: synthesis of highly substituted anilines.

A practical and novel one-pot organocatalytic selective process for the cascade synthesis of highly substituted o-hydroxydiarylamines and o-pyrrolidin-1-yldiarylamines is reported. Direct combination of amine-catalyzed cascade Knoevenagel/Michael/aldol condensation/decarboxylation and cascade enamine amination/isoaromatization of alkyl acetoacetates, aldehydes, and nitrosoarenes furnished the highly functionalized anilines with high yields.