Dipolarophile‐Steered Formal Stereodivergent Synthesis of 2,5‐cis/trans‐Pyrrolidines Based on Asymmetric 1,3‐Dipolar Cycloaddition of Imino Lactones.

Furuya, Shohei; Muroi, Kenji; Kanemoto, Kazuya; Fukuzawa, Shin‐ichi

The stereodivergent asymmetric synthesis of 2,5‐trans/cis pyrrolidines by 1,3‐dipolar cycloaddition using two different types of activated alkenes is described. When ylidene‐isoxazolones were employed as dipolarophiles, the Ag/(S,Sp)‐iPr‐FcPHOX‐catalyzed asymmetric [3 2] cycloaddition of imino lactones proceeded with 2,5‐trans selectivity. Subsequent decarboxylation of the isoxazolone rings produced pyrrolidines with 2,5‐trans stereoretention. In the reaction using acyclic enones as activated alkenes, the Ag/(R,Sp)‐ThioClickFerrophos complex‐catalyzed asymmetric [3 2] cycloaddition afforded 2,5‐cis substituted pyrrolidines in high yields and enantioselectivities. Therefore, these methods can be considered as a formal stereodivergent synthesis of 2,5‐cis/trans pyrrolidines.

PYRROLIDINE synthesis; RING formation (Chemistry); CARBONYL compounds; LACTONES; ASYMMETRIC synthesis; ISOXAZOLIDINES; SILVER catalysts; DECARBOXYLATION; ALKENES

Chemistry - A European Journal, 2023, Vol 29, Issue 66, p1

0947-6539

Academic Journal

10.1002/chem.202302609