The intermolecular deacylative coupling of unstrained ynones via C-C bond activation was accomplished by a CuCl-bpy system undermild reaction conditions. This protocol features facile cleavage of the C-C bond at room temperature, broad substrate scope, and efficient construction of important symmetric and unsymmetrical 1,3-diyne adducts through homo or cross coupling of ynones, respectively. The preliminary
1'-binaphthalene (Neolephos), which permits the palladium-catalyzed selective carbonylation under mild conditions, providing a general preparation of functionalized 1,3-enynes in good-to-high yields with excellent chemoselectivities. Synthetic applications that showcase the possibilities of this novel methodology include an efficient one-potsynthesis of 4-aryl-4H-pyrans as well as the rapid construction of various
A co-operative Ni–Cu system for C<sub>sp</sub>–C<sub>sp</sub> and C<sub>sp</sub>–C<sub>sp2</sub> cross-coupling providing a direct access to unsymmetrical 1,3-diynes and en-ynes
作者:Nirmalya Mukherjee、Debasish Kundu、Brindaban C. Ranu
DOI:10.1039/c4cc07413k
日期:——
An efficient cross coupling of alkynes with alkynyl and alkenyl halides catalysed by a Ni–Cu system without any ligand leading to the synthesis of a series of functionalised 1,3-di-ynes and en-ynes has been achieved.
Synthesis and structural characterization of a monomeric di-copper-substituted silicotungstate [γ-H2SiW10O36Cu2(μ-1,1-N3)2]4− and the catalysis of oxidative homocoupling of alkynes
acetonitrile, benzonitrile, and 1,2-dichloroethane, showed that complex 1 was present as a monomer of the di-copper-substituted γ-Keggin silicotungstate. Complex 1 could act as an effective homogeneous catalyst for the oxidativehomocoupling of various types of alkynes, including aromatic, aliphatic, and heteroatom-containing ones. The reaction possibly proceeds as follows: First, the ligand exchange
具有双-μ - 1,1-叠氮基配体的双铜取代的γ - Keggin硅钨酸盐TBA 4 [ γ- H 2 SiW 10 O 36 Cu 2(μ -1,1-N 3)2 ](1,TBA在水性介质中合成=(四TBA =四-正丁基铵)。1的阴离子部分的晶体结构是基-基末端叠氮桥联双铜取代的γ - Keggin硅钨酸盐的单体。的NMR和CSI-MS谱1在乙腈,苄腈和1,2-二氯乙烷等有机溶剂中的分析表明,配合物1作为双铜取代的γ - Keggin硅钨酸盐的单体存在。配合物1可以作为有效的均相催化剂,用于各种类型的炔烃(包括芳族,脂族和含杂原子的炔烃)的氧化均偶联。反应可能如下进行:首先,配体交换在1中的叠氮基之间进行。 和炔基通过二铜(II)-炔基中间体与还原的铜(I)物种形成相应的二炔,然后还原的物种被分子氧再氧化,氧化的物种与炔反应生成炔基中间的。
Scope and reaction mechanism of an aerobic oxidative alkyne homocoupling catalyzed by a di-copper-substituted silicotungstate
TBA = tetra-n-butylammonium) could act as an efficient reusable homogeneous catalyst for the aerobic oxidative alkyne homocoupling. Various kinds of structurally diverse terminalalkynes including aromatic, heteroaromatic, aliphatic, double bond-containing, silylacetylene, propargylicalcohol, and propargylic amine derivatives could selectively be converted into the corresponding diynes in the presence of I.