Cross-coupling reactions of gold(I) alkynyl and polyyndiyl complexes
作者:Wing Y. Man、Sören Bock、Natasha N. Zaitseva、Michael I. Bruce、Paul J. Low
DOI:10.1016/j.jorganchem.2010.11.026
日期:2011.5
Gold(I) alkynylcomplexes are shown to efficiently couple with aryl iodides under mild conditions in the presence of both Pd(II) and Cu(I) co-catalysts. The reaction is not gold catalysed, but rather the Au(I) centre serves to transfer the alkynyl moiety to Cu(I), which then enters the conventional Sonogashira cycles. Using this method, a small range of 1,4-disubstituted diynes, including examples
已显示金(I)炔基络合物在钯(II)和铜(I)助催化剂的存在下,在温和条件下可与芳基碘化物有效偶联。该反应不是金催化的,而是Au(I)中心用于将炔基部分转移至Cu(I),然后进入常规的Sonogashira循环。使用这种方法,已经直接从[[(Ph 3 P)AuC CC CAu(PPh 3)]和碘化芳基ArI制备了少量的1,4-二取代的二炔,包括差异取代的化合物ArC CC CAr'的实例。
Gold-Catalyzed Cadiot-Chodkiewicz-type Cross-Coupling of Terminal Alkynes with Alkynyl Hypervalent Iodine Reagents: Highly Selective Synthesis of Unsymmetrical 1,3-Diynes
作者:Xiangdong Li、Xin Xie、Ning Sun、Yuanhong Liu
DOI:10.1002/anie.201702833
日期:2017.6.6
A new and efficient method for the synthesis of unsymmetrical 1,3‐butadiynes by gold‐catalyzed C(sp)–C(sp) cross‐coupling of terminal alkynes with alkynyl hypervalent iodine(III) reagents has been developed. The reaction features high selectivity and efficiency, mild reaction conditions, wide substrate scope, and functional‐group compatibility, and is a highly attractive complement to existing methods
was developed. The reaction of 1,3-dialkynes with alkylhydrazines smoothly proceeded in dimethyl sulfoxide under suitable heating conditions to produce 1,3,5-trisubstituted pyrazoles in satisfactory to excellent yields. An efficient method to synthesize 1,3,5-trisubstituted pyrazoles was developed. The reaction of 1,3-dialkynes with alkylhydrazines smoothly proceeded in dimethyl sulfoxide under suitable
We show a facile method to prepare surface-clean monodispersed small and stable CuOx nanoparticles with controllable average sizes from below 1 nm up to similar to 5 nm without using bulk capping agent. Structural and surface characterizations show that the chemical states of CuOx nanoparticles and their interactions with O-2 are dependent on the particle size. To show their relevance to catalysis, the well-defined monodispersed CuOx nanoparticles have been used for oxidative coupling of alkynes. While the generally used CuCl catalysts presents a reaction induction period and agglomerate into CuOx nanoparticles during the reaction, the induction period disappears when monodispersed CuOx nanoparticles (similar to 2 nm) were used as catalyst. Supported CuOx nanoparticles on TiO2 behave in the same way as monodispersed CuOx nanoparticles. Kinetic, spectroscopic, and isotopic studies show that O-2 activation is the rate-controlling step and that the nature of the oxygen species formed on supported CuOx nanoparticles is dependent on the size of CuOx and determine the catalytic properties for oxidative coupling of alkynes.