A one-pot access to cycloalkano[1,2-a]indoles through an a intramolecular alkyl migration reaction in indolylborates

A novel one-pot protocol for the preparation of cycloalkano[1,2-]indoles by way of an intramolecular alkyl migration reaction in cyclic indolylborates is described. NaOMe was found to act as a successful trialkylboryl-protecting group against to the lithiation at the C2 of the indole ring. Treatment of cyclic indolylborates with electrophiles produced cycloalkano-[1,2-a]indoles. (c) 2005 Elsevier Ltd. All rights reserved.