Highly Effective and Broad-Spectrum Antimicrobial Quaternary Ammonium Salts Containing Camphene Structure: Preparation, Surface-Active Properties, and Bioassay.

A series of novel quaternary ammonium salts (QASs) (-) comprising a camphene moiety were synthesized for the first time. Fourteen examples were prepared from camphene through Prins reaction, halogenation, and quaternarization, successively. The structures of the synthesized QASs were analyzed by Fourier transform infrared spectroscopy, H NMR, C NMR and high-resolution mass spectrometry.

Visible-Light-Induced One-Pot Cross Coupling of -Sulfoximines with Toluene.

A one-pot cross-coupling reaction of -sulfoximines with toluene was realized by visible light-induced catalysis. The relatively inert toluene and sulfoximines were activated under mild conditions, and the functionalized sulfoximines were obtained via selective cross coupling. The reaction proceeded via consecutive steps including generation of the sulfoximine radical by visible-light catalysis, activation of toluene via hydrogen atom transfer (HAT), single-electron transfer (SET), and cross coupling to give -benzyl sulfoximines.

Anti-fatigue effects of pea ( L.) peptides prepared by compound protease.

In this study, the anti-fatigue effect of pea peptides in mice was explored. Mice were administrated with pea peptides for 30 days and then anti-fatigue related experiments and assays were performed. Swimming times of mice fed with pea peptides were very significantly longer than those of mice from control group in weight-loaded swimming test.

An efficient imidation of thioethers with nitrene in water.

The first imidation of thioethers with free nitrene in water was realized. N-Cbz sulfilimines are formed via imidation of thioethers with free nitrene generated from α elimination of nosyloxycarbamates. In this work, water is successfully applied as solvent for free nitrene, and transition metal catalyst is not needed.

Chiral GAP catalysts of phosphonylated imidazolidinones and their applications in asymmetric Diels-Alder and Friedel-Crafts reactions.

The design and synthesis of recyclable imidazolidinone catalysts using GAP chemistry/technique was described. Their applications in asymmetric Diels-Alder and Friedel-Crafts reactions with α,β-unsaturated aldehydes resulted in excellent yields and higher enantioselectivities than previous processes. As recyclable small molecular catalysts, phosphonylated imidazolidinones can be recovered and reused for up to three runs without costing significant decrease in catalytic activity.

Direct α-functionalization of simple aldehydes via oxidative N-heterocyclic carbene catalysis.

A direct α-functionalization of simple aldehydes under N-Heterocyclic Carbene (NHC) catalysis and direct generation of ester enolate equivalents from nonfunctionalized aldehydes are disclosed. The catalysis involves selective enolate generation from an oxidatively generated NHC-bounded ester intermediate as a key step. The ester enolate intermediates undergo stereoselective reactions with enones and trifluoromethyl ketones.

Highly enantioselective addition of enals to isatin-derived ketimines catalyzed by N-heterocyclic carbenes: synthesis of spirocyclic γ-lactams.

An N-heterocyclic carbene (NHC)-catalyzed annulation reaction of isatin N-Boc ketimines and enals is developed for the synthesis of spirocyclic oxindole-γ-lactams bearing one quaternary chiral center in good yields and excellent stereoselectivities (up to >20:1 dr and 99% ee).

Oxidative γ-addition of enals to trifluoromethyl ketones: enantioselectivity control via Lewis acid/N-heterocyclic carbene cooperative catalysis.

An oxidative γ-functionalization of enals under N-heterocyclic carbene (NHC) catalysis to give unsaturated δ-lactones is disclosed. Enantioselectivity control involving the relatively remote enal γ-carbon was achieved via Lewis acid [Sc(OTf)(3) or combined Sc(OTf)(3)/Mg(OTf)(2)] and NHC cooperative catalysis.

Formal Diels-Alder reactions of chalcones and formylcyclopropanes catalyzed by chiral N-heterocyclic carbenes.

Highly enantioselective (formal) hetero-Diels-Alder reactions between chalcones and formylcyclopropanes are disclosed. The challenging N-heterocyclic carbene (NHC)-bounded enolate intermediates from formylcyclopropanes were captured for new C-C bond forming reactions. The reaction products were obtained with high diastereo- and enantioselectivities and could be easily transformed to optically pure multisubstituted cyclohexane derivatives.

Synthesis of novel synthetic intermediates from the reaction of benzimidazole and triazole carbenes with ketenimines and their application in the construction of spiro-pyrroles.

2-(2-Alkoxycarbonyl-1-arylamino-1-propenyl)benzimidazolium and 5-(2-alkoxycarbonyl-1-arylamino-1-propenyl)triazolium salts were synthesized in good yields from the reaction of benzimidazole and triazole carbenes with ketenimines. Upon treatment with a base, both salts were converted into novel 1,3-dipoles which underwent [3+2] cycloaddition reactions with electron-deficient alkynes and allenes to produce benzimidazole-spiro-pyrroles or triazole-spiro-pyrroles. This work provides novel synthons for the construction of multifunctional spiro-pyrrole derivatives that are not easy accessible by other synthetic methods and are potentially amenable to further transformations.

An unprecedented chemospecific and stereoselective tandem nucleophilic addition/cycloaddition reaction of nucleophilic carbenes with ketenimines.

The first study of the reaction between nucleophilic carbenes and ketenimines is reported. The interaction of thiazole and benzothiazole carbenes with ketenimines proceeded in a chemospecific and stereoselective manner to produce thiazole- and benzothiazole-spiro-pyrrole derivatives generally in good yields. The reaction was proposed to proceed via a tandem nucleophilic addition of carbene to the C=N bond of ketenimine followed by a stepwise [3+2] cycloaddition of the 1,3-dipolar intermediate with the C=C bond of ketenimine.