<i>gem</i>-Selective Cross-Dimerization and Cross-Trimerization of Alkynes with Silylacetylenes Promoted by a Rhodium-Pyridine-<i>N</i>-Heterocyclic Carbene Catalyst
作者:Ramón Azpíroz、Laura Rubio-Pérez、Ricardo Castarlenas、Jesús J. Pérez-Torrente、Luis A. Oro
DOI:10.1002/cctc.201402327
日期:2014.9
The gem‐selective cross‐dimerization and ‐trimerization of silylacetylenes with alkynes through CH activation using a rhodium(I)–pyridine–N‐heterocyclic carbene catalyst have been developed. This reaction is applied to various aliphatic or aromatic terminal alkynes, internal alkynes, and gem‐1,3‐disubsituted enynes to afford the corresponding enynes and dienynes with high regio‐ and stereoselectivities
Regioselective Homo- and Codimerization of 1-Alkynes Leading to 2,4-Disubstituted 1-Buten-3-ynes by Catalysis of a (η<sup>5</sup>-C<sub>5</sub>Me<sub>5</sub>)<sub>2</sub>TiCl<sub>2</sub>/RMgX System
作者:Munetaka Akita、Hajime Yasuda、Akira Nakamura
DOI:10.1246/bcsj.57.480
日期:1984.2
A series of 1-alkynes (RC≡CH where R=Et, n-Pr, n-Bu, n-C6H13, cyclohexyl, Ph, Me3Si, Me3SiCH2, and Me3SiOCH2) was found to dimerize regioselectively (>99%) to 2,4-disubstituted 1-buten-3-ynes in 92–99% yields by catalysis of (η5-C5Me5)2TiCl2/i-PrMgBr at 30 °C in 1–3 h. The catalyst system is also effective for the regioselective codimerization of various 1-alkynes with 1-ethynylcyclohexene or ethynylbenzene.