Indium-assisted aluminium-based stereoselective allylation of prostereogenic α,α-disubstituted cycloalkanones and imines

Abstract

The use of a catalytic amount of InCl₃ in combination with Al⁰ for the allylation of a variety of prostereogenic α,α-disubstituted (hindered) cycloalkanones, 1,2-dione-based systems and various imino systems (CN functional groups) is reported. The stereoselective InCl₃-catalyzed Al-based allylation of various 2-substituted-2-carbethoxycycloalkanones gave the corresponding products with moderate to excellent diastereoselectivity. The allylation and propargylation of imines including α-imino esters using a catalytic amount of InCl₃ in combination with Al⁰ gave the corresponding allylated and propargylated compounds in moderate to good yields. If γ-substituted allylic halides were added to imino compounds, low to very good diastereoselectivity was obtained. The allylation of chiral N-tert-butylsulfinyl imine systems gave the corresponding products in moderate yields with good to excellent diastereoselectivity.