Siletanes (silacyclobutanes) represent a unique
class of silicon-based reagents that have enjoyed much success in
a number of synthetic applications including aldol reactions, allylations,
cross-coupling reactions, carbosilane oxidations, and ring
expansions. The manifestation of their strain in enhanced Lewis
acidity and in the ring opening to silanols accounts for their utility.
1-Chloro-1-methylsiletane can be used for the preparation of the
various siletane derivatives for these applications.
Grignard reagents react efficiently with 1-chloro-1-methylsiletane
to provide the corresponding aryl-, alkenyl-, or alkylsiletanes
(eqs 1–3).On the contrary, reactions with alkyllithiums are
limited to the reaction of 1 with a lithium acetylide (eq 4).The
reaction of 1 with an intermediate vinylalane obtained by hydroalumination
of 1-heptyne gave (E)-1-heptenylmethylsiletane
in >99/1 isomeric purity (eq 5).The reaction of 1 with LiAlD4
afforded 1-deuterio-1-methylsiletane (eq 6).
