Electronic control of product distribution in the [5+ 5]-coupling of ortho-alkynylbenzaldehyde derivatives and γ, δ-unsaturated carbene complexes

A Camacho-Davila, LSR Gamage, Z Wang…

Index: Camacho-Davila, Alejandro; Gamage, Lalith S.R.; Wang, Zhipeng; Herndon, James W. Tetrahedron, 2010 , vol. 66, # 27-28 p. 4954 - 4960

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Citation Number: 9

Abstract

The coupling of highly oxygenated ortho-alkynylbenzaldehyde derivatives with γ, δ-carbene complexes was evaluated systematically. In all of the electron-rich systems investigated the exclusive product of the reaction is the dihydrophenanthrene derivative. Only the extremely electron-withdrawing methanesulfonate group can prevent this process from occurring. The use of the base additive collidine resulted in a surprising yield enhancement but no other ...