A new class of chiral pyrrolidine-pyridine conjugate base catalysts for use in asymmetric Michael addition reactions was written by Ishii, Takaaki;Fujioka, Shingo;Sekiguchi, Yusuke;Kotsuki, Hiyoshizo. And the article was included in Journal of the American Chemical Society in 2004.Reference of 132635-95-1 This article mentions the following:
Direct catalytic asym. Michael addition reaction of ketones to nitroolefins, using chiral pyrrolidine-pyridine conjugate bases, e.g., I, as catalysts, is described. The desired 1,4-adducts were obtained in excellent yields with high enantio- and diastereoselectivities. In the experiment, the researchers used many compounds, for example, (S)-Tetrahydro-3H-pyrrolo[1,2-c][1,2,3]oxathiazole 1,1-dioxide (cas: 132635-95-1Reference of 132635-95-1).
(S)-Tetrahydro-3H-pyrrolo[1,2-c][1,2,3]oxathiazole 1,1-dioxide (cas: 132635-95-1) belongs to thiazole derivatives. Thiazole is a five-membered, unsaturated, planar, 蟺-excessive heteroaromatic containing one sulfur atom and one pyridine-type nitrogen atom at position 3 of the cyclic ring system. The pyridine-type nitrogen in the thiazole ring deactivates the ring for electrophilic substitution reactions, which is further reduced in acid due to protonation of the thiazole ring.Reference of 132635-95-1
Referemce:
Thiazole | C3H3NS – PubChem,
Thiazole | chemical compound | Britannica