Novel Route to Functionalized Indans via Formal (3 + 2) Cycloadditions of 1-Benzylbenzotriazoles with Alkenes.

Abstract α-Functionalized 1-benzylbenzotriazoles (3, 4 and 12), derived from the lithiation of 1-(2,3-dimethoxybenzyl)benzotriazole 2 followed by reactions with electrophiles, or from the condensation of benzyl alcohol 11 with benzotriazole, undergo formal [3 + 2] cycloadditions with styrenes upon treatment with ZnBr2 to give functionalized indans (9, 10, 13 and 14).