3-Bromopentadienylsilane: A new reagent for the introduction of a functional pentadienyl unit with fixed configuration
The (Z)-1-trimethylsilyl-3-bromopenta-2,4-diene 3 was prepared through a sequence involving the reductive silylation of butadiene, dibromocarbene addition on the resulting disilane 1, and thermolytic ring opening. With aldehydes, this new pentadienylsilane reacts exclusively via an S(E)' ' pathway. In the presence of an alcohol or a carbamate under Lewis acid activation, 3 yields, respectively, bromopentadienyl ethers or bromopentadienyl-protected amines.
Roux
M
Laboratoire de Synthese Organique associe au CNRS (ESA 6009), Faculte des Sciences de Saint Jerome, Avenue Escadrille Normandie-Niemen, 13397 Marseille Cedex 20, France.
Santelli
M
Parrain
JL