Addition of arylstannanes to alkynes givingortho-alkenylarylstannanes catalysed cooperatively by a rhodium complex and zinc chloride

Abstract

A Rh complex and ZnCl2 cooperatively catalyse the reaction of arylstannanes with alkynes giving ortho-alkenylarylstannanes.

1,4‐Migration of Transition Metals in Organic Synthesis

“…Aliphatic alkynes, aryl alkynes or non‐symmetric alkyl aryl alkynes were compatible substrates, and the later generally had good regioselectivity. The key steps are the vinyl‐to‐aryl 1,4‐Rh migration ( M73 to M74 ), and the transmetallation of ZnCl 2 with M74 to generate ortho ‐alkenylarylzinc reagents M75 …”

Rhodium-Catalyzed Expeditious Synthesis of Indenes from Propargyl Alcohols and Organoboronic Acids by Selective 1,4-Rhodium Migration over β-Oxygen Elimination

“…The 1,4-metal migrations through C–H bond activation are not only mechanistically intriguing processes but also key steps in transition-metal-catalyzed transformations, and great advances in organic synthesis have been made based on such processes . For example, novel C–H bond functionalization reactions were developed via 1,4-palladium migration by the groups of Larock, Lin, and others; as disclosed by the groups of Hayashi, Lam, Nishimura, and others, 1,4-rhodium and 1,4-iridium migrations played essential roles in a series of arylation-triggered cascade reactions; − Yoshikai and co-workers reported the formation of ortho -functionalized arylzinc/Grignard reagents via 1,4-cobalt and 1,4-chromium migrations. , Other metals including nickel, platinum, and iron have also been reported to undergo 1,4-migrations. Despite these sinificant advances, the scope of 1,4-metal migration is still greatly limited.…”

Copper-catalyzed arylstannylation of arynes in a sequence

“…Please do not adjust margins Please do not adjust margins by transmetalation. 10 However, the use of precious metal or rare-earth catalysts is still inevitable for the transmetalationbased arylstannylation. We report herein on a unique catalysis of a Cu(I) salt, an abundant base metal, for the arylstannylation of arynes involving the transmetalation as a key step (Fig.…”

“…8). Quantitative protodestannylation and C-C bond-forming reactions (the MKS coupling and oxidative homocoupling), which furnished an ortho-teraryl (9) or an ortho-tetraaryl (10), were also achievable. Furthermore, the transmetalation (not oxidative addition)-based catalytic cycle allowed a C(aryl)-Br bond of 1n to be compatible with the arylstannylation, affording multihalogenated orthostannylbiaryl 3nj.…”