Chemoselective Switch in the Asymmetric Organocatalysis of 5H-Oxazol-4-ones and N-Itaconimides: Addition-Protonation or [4+2] Cycloaddition.

Citation data:

Angewandte Chemie (International ed. in English), ISSN: 1521-3773, Vol: 55, Issue: 4, Page: 1299-303

Publication Year:
Usage 9
Abstract Views 9
Captures 4
Readers 4
Social Media 3
Tweets 3
Citations 27
Citation Indexes 27
Repository URL:
Zhu, Bo; Lee, Richmond; Li, Jiangtao; Ye, Xinyi; Hong, San-Ni; Qiu, Shuai; Coote, Michelle L.; Jiang, Zhiyong
Chemical Engineering; Chemistry; Chemoselectivity; Chirality; Density functional calculations; Organocatalysis; Synthetic methods
Most Recent Tweet View All Tweets
article description
We report a synthetic strategy for a chemoselective switch and a diastereo-divergent approach for the asymmetric reaction of 5H-oxazol-4-ones and N-itaconimides catalyzed by l-tert-leucine-derived tertiary amine-urea compounds. The reaction was modulated to harness either tandem conjugate addition-protonation or [4+2] cycloaddition as major product with excellent enantio- and diastereoselectivities. Subjecting the enantio-enriched cycloaddition products to a basic silica gel reagent yields the diastereomer vis-à-vis the product directly obtained under conditions for addition-protonation, thus opening a diastereo-divergent route for creating 1,3-tertiary-hetero-quaternary stereocenters. Quantum chemical studies further provide stereochemical analysis for the [4+2] process and a plausible mechanism for this chemoselective switch is proposed.