Photoredox Propargylation of Aldehydes Catalytic in Titanium
作者:Francesco Calogero、Andrea Gualandi、Marco Di Matteo、Simone Potenti、Andrea Fermi、Giacomo Bergamini、Pier Giorgio Cozzi
DOI:10.1021/acs.joc.1c00521
日期:2021.5.7
A practical and effective photoredox propargylation of aldehydes promoted by 10 mol % of [Cp2TiCl2] is presented. No stoichiometric metals or scavengers are used for the process. A catalytic amount of the cheap and simply prepared organic dye 3DPAFIPN is used as the reductant for titanium. The reaction displayed a broad scope, and no traces of allenyl isomers were detected for simple propargyl bromide
A tandem oxidativecouplingreaction of β-ketoallenes and arenes was developed, which leads to the formation of 2-furylmethylarenes using AuCl3 and phenyliodine diacetate. The AuIII salt catalyzed the cyclization of β-ketoallenes to form a 2-furylmethyl gold intermediate, and the subsequent C–H functionalization of arenes proceeded smoothly. During the oxidativecoupling, nucleophilic additions occurred
InI3- or ZnI2-Catalyzed Reaction of Hydroxylated 1,5-Allenynes with Thiols: A New Access to 3,5-Disubstituted Toluene Derivatives
作者:Jie Ma、Lingling Peng、Xiu Zhang、Zhe Zhang、Melody Campbell、Jianbo Wang
DOI:10.1002/asia.201000267
日期:——
undergo direct addition of the nucleophiles to the unsaturated bonds or trigger subsequent rearrangement reactions. This chemistry has witnessed increasing development in recent years. In this report, we have focused on the metal‐catalyzed reactions of a variety of substituted propargyl allenic alcohols and thiophenols using indium(III) and zinc(II) catalysts, which can activate both the alcohol and alkyne
Gold-Catalyzed Regioselective Synthesis of 2- and 3-Alkynyl Furans
作者:Yifan Li、Jonathan P. Brand、Jérôme Waser
DOI:10.1002/anie.201302210
日期:2013.6.24
Chemical Matching: C2‐ or C3‐alkynylated furans were selectively synthesized by using gold catalysis. Direct C–H alkynylation of furans was achieved with C2 selectivity, and a domino cyclization/alkynylation process starting from allenes gave C3‐alkynylated products. The exact matching of the structure of the gold catalyst and an electrophilic hypervalent iodine reagent was essential for success.
Ruthenium hydride catalyzed silylvinylation of terminal alkynes under ethylene atmosphere at 80 psi
作者:Alexandre D.C. Dixon、Robert J. Wilson、Daniel D. Nguyen、Daniel A. Clark
DOI:10.1016/j.tetlet.2017.09.023
日期:2017.10
The development of methods for the stereoselectivesynthesis of polysubstituted 1,3-dienes is a challenge to synthetic chemistry. Herein is reported a selective approach for the synthesis of polysubstituted 1,3-dienes using the ruthenium hydride catalyzed intramolecular silylvinylation of alkynes under 80 psi of ethylene gas. This strategy affords a single diene isomer, is applicable to substrates