1,3- and 1,6-Addition of electronegatively substituted olefins to co-ordinated cycloheptatriene and N-methoxycarbonylazepine: X-ray diffraction study of the tricarbonylcycloheptatrieneiron–tetracyanoethylene adduct

Abstract

A single-crystal X-ray diffraction study establishes that tetracyanoethylene undergoes a 1,3-addition reaction to tricarbonylcycloheptatrieneiron, with formation of a novel 2,3,4,6-tetrahapto-bonded system: the corresponding reaction with tricarbonyl-N-methoxy-carbonylazepine-ruthenium or -iron affords, respectively, a 1,3 adduct or a mixture of 1,6 and 1,3 adducts.