Simultaneous diversity-oriented synthesis of diverse benzo[d][1,3]thiazine libraries from identical substrates

[Display omitted] Using o-isothiocyanato-(E)-cinnamaldehydes as powerful and versatile precursors, a facile domino reaction for the simultaneous formation of a compound library similar to natural products 3,4-dihydroquinazoline derivatives and 2,4-dihydro-1H-benzo[d][1,3]thiazine derivatives has been developed. The domino reaction of o-isothiocyanato-(E)-cinnamaldehydes with hydroxylamine resulted in the simultaneous formation of N/S-heterocycles and N/N-heterocycles, generating six classes of previously unknown 2,4-dihydro-1H-benzo[d][1,3]thiazine derivatives with various functional groups. This strategy is a typical example of diversity-oriented synthesis method.