Synthetic Application and Structural Elucidation of Axially Chiral Dicarboxylic Acid: Asymmetric Mannich-type Reaction with Diazoacetate, (Diazomethyl)phosphonate, and (Diazomethyl)sulfone
acids in organic chemistry, have rarely been used as chiral Brønsted acid catalysts. In this context, we developed axially chiral dicarboxylic acid and evaluated its catalytic activity in asymmetricMannich-typereaction of aromatic aldehyde-derived N-Boc imines and tert-butyl diazoacetate. To demonstrate the remarkable generality of this catalytic system, tert-butyl diazoacetate was replaced with its