Marichev, Kostiantyn O. published the artcileSynthesis of Chiral Tetrasubstituted Azetidines from Donor-Acceptor Azetines via Asymmetric Copper(I)-Catalyzed Imido-Ylide [3+1]-Cycloaddition with Metallo-Enolcarbenes, Related Products of benzoxazole, the publication is Angewandte Chemie, International Edition (2019), 58(45), 16188-16192, database is CAplus and MEDLINE.
The all-cis stereoisomers of tetrasubstituted azetidine-2-carboxylic acids and derivatives that possess three chiral centers have been prepared in high yield and stereocontrol from silyl-protected Z-γ-substituted enoldiazoacetates and imido-sulfur ylides by asym. [3+1]-cycloaddition using chiral sabox copper(I) catalysis [e.g., I + II → III (83%, 90% ee)] followed by Pd/C catalytic hydrogenation (III → IV). Hydrogenation of the chiral p-methoxybenzyl azetine-2-carboxylates occurs with both hydrogen addition to the C=C bond and hydrogenolysis of the ester.
Angewandte Chemie, International Edition published new progress about 1239015-11-2. 1239015-11-2 belongs to benzoxazole, auxiliary class TOX Ligands, name is (3aS,3a’S,3a”S,8aR,8a’R,8a”R)-2,2′,2″-(Propane-1,2,2-triyl)tris(8,8a-dihydro-3aH-indeno[1,2-d]oxazole), and the molecular formula is C33H29N3O3, Related Products of benzoxazole.
Referemce:
https://en.wikipedia.org/wiki/Benzoxazole,
Benzoxazole | C7H5NO – PubChem