Synthesis of 1,3-butadiene derivatives and 1,1'-cyclopropylvinylcyclopropane using organozirconium complex

Abstract

A convienient synthetic method for the preparation of 1-phenylseleo-4-iodo-1, 3-butadiene derivatives has been developed. It was performed by transmetallation of symmetrical and unsymmetrical five-membered zirconacycles using phenylseleneyl bromide and iodine step by step. The reactions proceeded with chemo-and stereo-specific manners. 1,4-Bis(phenylseleno)-1, 3-butadiene derivatives were prepared using different scheme where 2 equi. of phenylselenenyl bromide was added step by step over two stage via transmetalation of zirconacylclopentadiene derivatives. Using privous study of the rearrangement of bromoalkyl zirconocenes which is unusaual intramolecular rearrangement of alkyl and alkenyl group from zirconocene to alkyl carbon, 1-1``-cyclopropyl-1-vinylcyclopropane was able to prepare via double rearrangement of vinyl or alkyl moiety from zirconocene to cyclopropane with commensurate breaking of the C-Br bond of bromocyclopropane.