Assembly of Complex 1,4‐Cycloheptadienes by (4+3) Cycloaddition of Rhodium(II) and Gold(I) Non‐Acceptor Carbenes

Abstract

The formal (4+3) cycloaddition of 1,3‐dienes with Rh(II) and Au(I) non‐acceptor vinyl carbenes, generated from vinylcycloheptatrienes or alkoxyenynes, respectively, leads to 1,4‐cycloheptadienes featuring complex and diverse substitution patterns, including natural dyctiopterene C′ and a hydroxylated derivative of carota‐1,4‐diene. A complete mechanistic picture is presented, in which Au(I) and Rh(II) non‐acceptor vinyl carbenes were shown to undergo a vinylcyclopropanation/Cope rearrangement or a direct (4+3) cycloaddition that takes place in a non‐concerted manner.