THE SYNTHESIS OF 1,1'-SPIROALKANE OR FUSED ANNULATED 1,2,3,4-TETRAHYDROISOQUINOLINES USING A HIGHLY REACTIVE FORMAMIDINE FOR METALATION ALKYLATION

We have, on numerous occasions, reported on the use of formamidines in the metalation of the a-carbon of amines and their subsequent alkylation to chiral and achiral amino compounds1 (Scheme I). In a recent report from this laboratory,2 we also described a new formamidine, which we felt was considerably more efficient in mediating metalation of the a-carbon (Scheme I, R = 2-(methoxymethyl)aniline). Further studies have now uncovered a considerably better formamidine 5 which is readily available and provides the quaternary substitution product in very good yields. © 1990, American Chemical Society. All rights reserved.