d selective hydroarylation of unsymmetrical alkynes represents the state‐of‐art in organic chemistry, and still mainly relies on the use of precious late‐transition‐metal catalysts. Reported herein is an unprecedented MnI‐catalyzed hydroarylation of unsymmetrical 1,3‐diyne alcohols with commercially available arylboronic acids with predictive selectivity. This method addresses the challenges in regio‐
Nickel-Catalyzed Oxidative Coupling Reactions of Two Different Terminal Alkynes Using O<sub>2</sub> as the Oxidant at Room Temperature: Facile Syntheses of Unsymmetric 1,3-Diynes
作者:Weiyan Yin、Chuan He、Mao Chen、Heng Zhang、Aiwen Lei
DOI:10.1021/ol8027863
日期:2009.2.5
Two different terminal alkynes now can be coupled together in the presence of NiCl2·6H2O/CuI by using an excess of one of the terminal alkyne substrates. The new method employed 20 mol % TMEDA as the ligand and environmentally benign O2 or air as the oxidant. It is the first example using Ni-salt as catalyst by employing air or O2 as oxidant, which led to efficient heterocoupling of two different alkynes
现在,可以通过使用过量的一种末端炔烃基质在NiCl 2 ·6H 2 O / CuI存在下将两个不同的末端炔烃偶联在一起。该新方法采用20 mol%的TMEDA作为配体,并采用对环境无害的O 2或空气作为氧化剂。这是第一个使用镍盐作为催化剂,通过使用空气或O 2作为氧化剂的例子,这导致了两个不同炔烃的有效异质偶联。
Benzocyclobutadienes: An Unusual Mode of Access Reveals Unusual Modes of Reactivity
作者:Xiao Xiao、Brian P. Woods、Wen Xiu、Thomas R. Hoye
DOI:10.1002/anie.201803872
日期:2018.7.26
The reaction of an aryne with an alkyne to generate a benzocyclobutadiene (BCB) intermediate is rare. We report here examples of this reaction, revealed by Diels–Alder trapping of the BCB by either pendant or external electron‐deficient alkynes. Mechanistic delineation of the reaction course is supported by DFT calculations. A three‐component process joining the benzyne first with an electron‐rich