title: Stereoselective synthesis and reactions of secondary alkyllithium reagents functionalized at the 3-position.
abstract: Secondary alkyllithium reagents bearing an OTBS group (TBS=tert-butyldimethylsilyl) at the 3-position can be prepared stereoconvergently through an I/Li exchange from a diastereomeric mixture of the corresponding secondary alkyl iodides. These lithium reagents react with a range of electrophiles, including carbon electrophiles, with retention of configuration to yield various 1,3-difunctionalized derivatives with good diastereoselectivities. Kinetic studies show that the 3-siloxy group strongly accelerates the epimerization at the lithium-substituted carbon atom. This method offers a new way to construct chiral open-chain molecules with excellent stereoselectivity.
authors: Department Chemie, Ludwig-Maximilians-Universität München, Butenandtstr. 5-13, 81377 München (Germany).
authors: Kohei
authors: K
authors: Moriya
authors: Dorian
authors: D
authors: Didier
authors: Meike
authors: M
authors: Simon
authors: Jeffrey M
authors: JM
authors: Hammann
authors: Guillaume
authors: G
authors: Berionni
authors: Konstantin
authors: K
authors: Karaghiosoff
authors: Hendrik
authors: H
authors: Zipse
authors: Herbert
authors: H
authors: Mayr
authors: Paul
authors: P
authors: Knochel
keywords: carbanions; diastereoselectivity; kinetics; lithiation; nucleophilic substitution