Synthesis and X-ray crystal structure analysis of a phosphorus analogue of(1,2,3-eta)-trans-butadienyl complexes

Metalation of the 1-phenyl-2-isopropylidene - phosphirane P-W(CO)(5) comple x (1) by lithium diisopropylamide occurs at the ring CH, and cleaves the ri ng to give the corresponding (3,3-dimethyl-allen-1-yl)phenylphosphide P-W(C O)(5) complex (2). The reaction of 2 with [CpFe(CO)(2)I] then yields the mu -phosphido complex 3 whose heating at 110 degreesC finally gives the (1,2, 3-eta)-trans-1-phenyl-4,4-dimethyl-1-phosphabutadienyl complex (4). The str ucture of 4 shows the syn-coplanar stereochemistry of the W-P-C-H unit with a short P-C bond at 1.773 Angstrom. The methylene substituent forms an ang le of 145.4 degrees with the C-C bond of the eta (3)-allyl unit. (C) 2001 E lsevier Science B.V. All rights reserved.