Switchable multipath cascade cyclization to synthesize bicyclic lactams and succinimides via chemodivergent reaction.

Herein, a novel switchable multipath cascade cyclization via chemodivergent reaction between readily available ketoamides and deconjugated butenolides was developed to efficiently synthesize γ-lactone fused γ-lactams and succinimide fused hemiketals. The Aldol/aza-Michael reaction and Aldol/imidation/hemiketalization reaction were enabled by catalytic amounts of two bases, namely tetramethyl guanidine and NaOAc. A wide range of substrate scope with diverse functional group compatibility was demonstrated to deliver the corresponding products with good yield and excellent diastereoselectivity (>60 examples).

Highly regioselective synthesis of lactams via cascade reaction of α,ß-unsaturated ketones, ketoamides, and DBU as a catalyst.

Herein, the aldol/Michael cascade reaction on the ß,γ-positions of α,ß-unsaturated ketones with ketoamides to construct bicyclic lactams via DBU catalysis has been developed. The substrates were well-tolerated with high regio- and diastereoselectivities in moderate to good yields (32 examples). The control experiments revealed that the hydrogen of the amide was the key factor.