Cheng-Zhi Gu

Organocatalytic direct difluoromethylation of aldehydes and ketones with TMSCF2H

An organic Lewis base promoted direct difluoromethylation reaction of carbonyl compounds with Me3SiCF2H has been studied. The Schwesingers superbase can efficiently activate the Si–CF2H bond and initiate the difluoromethylation of aldehydes and ketones under very mild conditions, producing difluoromethyl adducts in 42–99% yields.

Aryne-induced dearomatized phosphonylation of electron-deficient azaarenes

An aryne-induced dearomatized phosphonylation reaction has been developed. Electron-deficient azaarenes such as quinolines, isoquinolines, phenanthroline and acridine undergo multicomponent reaction with arynes and dialkylphosphites to afford the corresponding dearomatized phosphonylated heterocycles in 50–90% yields.

N-heterocyclic carbene-catalysed pentafluorophenylation of aldehydes

N-heterocyclic carbenes have been utilized as highly efficient organocatalysts to catalyse multifluorophenylation of aldehydes with pentafluorophenyltrimethylsilane or bis(trimethylsilyl)tetrafluorobenzene to afford the corresponding fluorinated adducts in 49–99% yields.

Two new cucurbitane-type triterpenoid saponins isolated from ethyl acetate extract of Citrullus colocynthis fruit

Two new cucurbitacins I (1 and 2), together with eight known compounds (3–10), were isolated from the ethyl acetate extract of the fruit of Citrullus colocynthis. Compounds 3, 5–9 were isolated from C. colocynthis for the first time. The structures of new compounds were determined primarily from IR, HR-MS, 1D-, and 2D-NMR analysis.

Metal-free oxidation of secondary benzylic alcohols using aqueous TBHP

ABSTRACT We report a simple, yet efficient metal-free oxidation of secondary benzylic alcohols in the presence of t-butyl hydroperoxide (70% TBHP) with high yields of up to 98%. This type of reaction can be carried out using a wide variety of substrates, requires no other organic solvent, and proves to be tolerant toward a variety of different functional groups. GRAPHICAL ABSTRACT

Diastereoselective Synthesis of γ-Butenolides Catalyzed by Potassium tert-Butoxide

Abstract Potassium tert-butoxide (0.1 mol%) catalyzed a vinylogous Mukaiyama aldol reaction between aromatic and aliphatic aldehydes with 2-(trimethylsilyloxy)furan. The corresponding γ-butenolides were obtained in good yields with good diastereoselectivities. GRAPHICAL ABSTRACT

N-heterocyclic carbene-catalyzed regio- and stereoselective hydrothiolation reaction of alkynes

Abstract N-heterocyclic carbenes (NHCs) have been utilized as Brønsted base to catalyze the hydrothiolation reaction between alkynes and thiols to produce the vinyl sulfides stereoselectively. Graphical Abstract Graphical Abstract

The self-assembly of monosubstituted BODIPY and HFBI-RGD

A novel fluorescent probe was constructed by the self-assembly of monosubstituted BODIPY and a novel targeted hydrophobin named hereafter as HFBI-RGD. Optical measurements and theoretical calculations confirmed that the spectral properties of the probe were greatly influenced by the BODIPY structure, the appropriate volume of BODIPY and the cavity of HFBI-RGD. The experiments in vivo and ex vivo demonstrated that the probe had excellent ability for tumor labelling.