One-Pot Asymmetric Synthesis of Alkylidene 1‑Alkylindan-1-ols Using Brønsted Acid and Palladium Catalysis

A one-pot
catalytic enantioselective allylboration/Mizoroki–Heck
reaction of 2-bromoaryl ketones has been developed for the asymmetric
synthesis of 3-methyleneindanes bearing a tertiary alcohol center.
Brønsted acid-catalyzed allylboration with a chiral BINOL derivative
was followed by a palladium-catalyzed Mizoroki–Heck cyclization,
resulting in selective formation of the exo-alkene.
This novel protocol provides a concise and scalable approach to 1-alkyl-3-methyleneindan-1-ols
in high enantiomeric ratios (up to 96:4 er). The potential of these
compounds as chiral building blocks was demonstrated with efficient
transformation to optically active diol and amino alcohol scaffolds.