Novel thermal rearrangement reactions: rearrangement stereospecificity of complex [Fe2(CO)2(µ-CO)2(µ-t-BuC5H3Me2GeGeMe2C5H3Bu-t)]

Abstract

Thermal treatment of 1,2-bis(3-tert-butylcyclopentadienyl)tetramethyldigermane with [Fe(CO)₅] in xylene gave the diiron complex [Fe₂(CO)₂(µ-CO)₂(µ-3-t-BuC₅H₃Me₂GeGeMe₂C₅H₃Bu-t-3)] 1 existing as a mixture of cis and trans isomers (1c and 1t) which were separated by preparative TLC. When the two isomers were heated in xylene the cis substrate (1c) rearranged to a trans product [Fe₂(CO)₄(µ-3-t-BuC₅H₃GeMe₂)₂] 2t, while the trans substrate (1t) afforded a cis product 2c. This indicates that the rearrangement reaction is stereospecific, which is consistent with previous results. Molecular structures of 1c, 1t, 2t, and 2c were determined by X-ray diffraction.