AbstractReported herein is a conceptually novel organocatalytic strategy for the formylation of boronic acids. New reactivity is engineered into the α-amino-acid-forming Petasis reaction occurring between aryl boronic acids, amines, and glyoxylic acids to prepare aldehydes. The operational simplicity of the process and its ability to generate structurally diverse and valued aryl, heteroaryl, and α,β-unsaturated aldehydes containing a wide array of functional groups, demonstrates the practical utility of the new synthetic strategy.

AbstractReported herein is a conceptually novel organocatalytic strategy for the formylation of boronic acids. New reactivity is engineered into the α-amino-acid-forming Petasis reaction occurring between aryl boronic acids, amines, and glyoxylic acids to prepare aldehydes. The operational simplicity of the process and its ability to generate structurally diverse and valued aryl, heteroaryl, and α,β-unsaturated aldehydes containing a wide array of functional groups, demonstrates the practical utility of the new synthetic strategy.

A highly enantioselective addition of alcohols to cyclic trifluoromethyl ketimines is developed catalyzed by quinine-thiourea, giving biologically interesting N,O-ketals in up to 99% yield and 96% ee.

•[4+2] Annulation of aldehydes and o-quinone methides.•Facile synthesis of dihydrocoumarins.•Use of simple secondary amine as catalyst.A [4+2] annulation of aldehydes and o-quinone methides catalyzed by a secondary amine is developed. This process leads to biologically important dihydrocoumarins in moderate to good yields after oxidation. In addition, the employment of a chiral secondary amine catalyst allows access to optically active dihydrocoumarins with up to 64% ee.

A highly enantioselective aza-Friedel–Crafts (aza-F-C) reaction of cyclic trifluoromethyl ketimines and naphthols/phenols was developed with fluorenyl-substituted quinine-squaramide as the catalyst. This protocol enables direct access to biologically important chiral trifluoromethyl dihydroquinazolinones with up to 99% yields and up to 99% ee’s.

A highly enantioselective addition of alcohols to cyclic trifluoromethyl ketimines is developed catalyzed by quinine-thiourea, giving biologically interesting N,O-ketals in up to 99% yield and 96% ee.