Science of Synthesis

Sawamura, M.; Shimizu, Y., Science of Synthesis Knowledge Updates, (2024) 2, 237.

Conjugate addition of nitrogen-based nucleophiles is feasible with the aid of boron catalysts.[‌68‌–‌72‌] Specifically, the integrated chiral boron compound ‌58‌, comprising a boronic acid and a thiourea moiety, is a powerful catalyst for the conjugate addition of O-benzylhydroxylamine to α,β-unsaturated carboxylic acids to afford β-amino acid derivatives ‌59‌ (after conversion into the corresponding methyl ester) with high enantioselectivities (‌Scheme 31‌).[‌70‌–‌72‌] The addition of benzoic acid improves enantioselectivities.

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References