Synthesis

Cobalt-Catalysed [6+ 2] Cycloaddition of Internal Alkynes and Terminal Alkenes with Cycloheptatriene

G Hilt, A Paul, C Hengst

Index: Hilt, Gerhard; Paul, Anna; Hengst, Christoph Synthesis, 2009 , # 19 p. 3305 - 3310

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Citation Number: 11

Abstract

Abstract The cobalt-catalysed [6+ 2] cycloaddition of cycloheptatriene with internal alkynes as well as with terminal alkenes is described. The cycloaddition process is most efficiently catalysed by cobalt dibromide [bis (triisopropylphosphite)] complexes in dichloromethane as the solvent of choice. In the cobalt-catalysed reaction of cycloheptatriene with norbornene an unexpected tricyclic [2+ 2] cycloaddition product was isolated in excellent yields.