Atroposelective attack of nucleophiles on 2-formyl-1-naphthamides and their derivatives: chelation and non-chelation control

Organometallic nucleophiles attack 2-formyl-1-naphthamides to give secondar y alcohols with widely varying atroposelectivity. By careful choice of reag ent, selectivities of up to > 99:1 in favour of either the anti or the syn atropisomer can be obtained. Ethers and amines may be synthesised atroposel ectively from acetals or imines. The sense of the selectivity is determined by the reactive conformation of the Ar-CHO bond, itself dependent on the c oordinating and chelating ability of the nucleophile's counterion. The role s of conformation, Lewis acids, and chelation/non-chelation control in rela tion to stereoselectivity are discussed.