Regio- and Stereoselective Synthesis of Homoallylic Alcohols Based on the Use of (3-Chloroprop-1-en-1-yl)boronates

Abstract

A set of (3-chloroprop-1-en-1-yl)boronates 10 were synthesised, starting from (3-chloroprop-1-en-1-yl)bis(isopinocampheyl)borane. Quaternisation of 10 by Grignard methodology afforded ''ate'' species 14, which underwent spontaneous anionotropic rearrangement to give the substituted allylboronates 15. By a suitable choice of the diol component [a]

(E)-2-(1,1-Dicyclohexyl-3-phenylallyl)-5,5-dimethyl-1,3,2-dioxaborinane

“…For the synthesis and applications of allylboronic esters, see: Lombardo et al (2002); Carosi & Hall (2007); Althaus et al…”

Recent Advances in the Preparation of Allylboronates and Their Use in Tandem Reactions with Carbonyl Compounds

“…A preparative method similar to the previous one is the vinylogous Matteson rearrangement of pinacol 3-chloroallylboronate (45) exploited by Lombardo and coworkers (Equation 26) [70]. Here, a Grignard reagent adds to 45 with allylic rearrangement to give substituted allylboronate 46.…”

Allylation of Aldehyde and Imine Substrates with in situ Generated Allylboronates — A Simple Route to Enantioenriched Homoallyl Alcohols.

“…The NMR spectrum is identical with that reported in the literature. [45] [α] D 20 = +42.2 (c = 0.36, CHCl 3 ) for 53 % ee. The configuration was assigned on the basis of the optical rotation data reported for the phenyl analog (R)-5j (see above).…”