Silane, trimethyl(2-methylene-3-buten-1-yl)-

Physical properties

bp 69–70 °C/80 mmHg.

Uses

2-Trimethylsilylmethyl-1,3-butadiene is an isoprenylation reagent; Diels–Alder diene; reactant in Formation of π-Allylic Complex Followed by Acyldemetalation.

Preparation

2-Trimethylsilylmethyl-1,3-butadiene is prepared most conveniently by the coupling reaction of the Grignard reagent prepared from (chloromethyl)trimethylsilane with 2-chloro-1,3-butadiene (chloroprene) in the presence of a catalytic amount of Ni[Ph2P- (CH2)3PPh2]Cl2 (91% yield) (eq 1). Alternatively, it can be prepared by the reaction of the same Grignard reagent with allenylmethyl phosphate in 57¨C73% yield (eq 2). Direct metalation of isoprene followed by the reaction with chlorotrimethylsilane gives 2-trimethylsilylmethyl-1,3-butadiene in low yield. Thermal isomerization of 1-trimethylsilylmethylcyclobutene to 2-trimethylsilylmethyl-1,3-butadiene has also been reported.