An Efficient [4 + 2 + 1] Entry to Seven-Membered Rings
作者:Yike Ni、John Montgomery
DOI:10.1021/ja046147y
日期:2004.9.1
A new nickel-catalyzed procedure for the [4 + 2 + 1] cycloaddition of trimethylsilyl diazomethane with alkynes tethered to dienes has been developed. A broad range of unsaturated substrates participate in the sequence, and stereoselectivities are generally excellent. Three possible mechanisms are proposed, and each involves the generation of a transient nickel carbene species.