Pd-Catalyzed Addition of Organoboronic Acids to Alkynes at Room Temperature
作者:Chang Ho Oh、Arun Kumar Gupta、Ki Seong Kim
DOI:10.1055/s-2005-862362
日期:——
Combination of Pd(OAc) 2 with 2-bromo-1,3-bis-[diphenylphosphenomethyl)]benzene (1) or 2-bromo-1,3-bis-[di-tert-butylphosphenomethyl)]benzene (3) catalyzed hydroarylations and hydroalkenylations of various alkynes more efficiently in terms of reaction time and temperature.
Single-Isomer Trisubstituted Olefins from a Novel Reaction of (<i>E</i>)-β-Chloro-α-iodo-α,β-unsaturated Esters and Amides
作者:Julie Simard-Mercier、Jojo Liu Jiang、Michael L. Ho、Alison B. Flynn、William W. Ogilvie
DOI:10.1021/jo8008325
日期:2008.8.1
converted to single isomer trisubstitutedolefins bearing three different carbon substituents by cross-coupling under reflux. Mechanistic investigations suggest that this process transfers a hydrogen from the boronic acid to the α-position of the substrate and then introduces an aryl group to the β-position of the intermediate template while replacing chloride. The reaction is highly stereoselective
Visible‐Light‐Mediated Heterocycle Functionalization via Geometrically Interrupted [2+2] Cycloaddition
作者:Mihai V. Popescu、Aroonroj Mekereeya、Juan V. Alegre‐Requena、Robert S. Paton、Martin D. Smith
DOI:10.1002/anie.202009704
日期:2020.12.14
cyclization in the triplet excited state to yield a 1,4‐diradical; intersystem crossing leads preferentially to the closed shell singlet zwitterion. This is geometrically restricted from undergoing recombination to yield a cyclobutane by the planarity of the amide substituent. A prototropic shift leads to the observed bicyclic products in what can be viewed as an interrupted [2+2] cycloaddition.
Electrochemical oxidative <i>Z</i>-selective C(sp<sup>2</sup>)–H chlorination of acrylamides
作者:James Harnedy、Mishra Deepak Hareram、Graham J. Tizzard、Simon J. Coles、Louis C. Morrill
DOI:10.1039/d1cc05824j
日期:——
An electrochemical method for the oxidative Z-selective C(sp2)–H chlorination of acrylamides has been developed. This catalyst and organic oxidant free method is applicable across various substituted tertiary acrylamides, and provides access to a broad range of synthetically useful Z-β-chloroacrylamides in good yields (22 examples, 73% average yield). The orthogonal derivatization of the products was