Atropoenantioselective Arylation of 5‐Amino‐Isothiazoles with Methyl p‐Quinone Carboxylate

Abstract

Isothiazole units exist in many natural products and pharmaceutics. Up to now, construction of isothiazolecontaining axially chiral biaryls has not been reported yet. Herein we disclose a chiral phosphoric acid catalyzed atropoenantioselective arylation of 5-amino-isothiazoles with methyl p-quinone carboxylate. Various novel isothiazole-[a] Y.

Organocatalytic (1+4)‐Annulations of MBH Adducts with Electron‐Deficient Systems

“…Encouragingly, a broad scope of MBH carbonates 74 and α,β-unsaturated imines 75 were compatible to furnish chiral 2-pyrrolines 76 in moderate to high yields with excellent diastereo-and enantioselectivities (Scheme 22). [34] Significantly, the ester group of MBH carbonates 74 had a slight influence on the yield and enantioselectivity. The effect of the substituent on nitrogen atom of imines 75 could also be negligible.…”

Catalyst-free reaction of 2-(4H-benzo[d][1,3]oxazin-4-yl)acrylates: synthesis of 1,2-dihydroquinolines and 2,3-dihydropyrroles

“…15b,c Independently, we also achieved a chiral phosphine-catalyzed enantioselective [4+1]-annulation of a,b-unsaturated imines and MBH carbonates for the synthesis of chiral 2,3-dihydropyrroles. 16 Notably, the annulation of MBH carbonates has become a common tool for the construction of structurally diverse carbo-and heterocycles. 17 Given the importance of benzoxazine and acrylate units, and in continuation of our efforts on the organocatalytic reactions of MBH carbonates, 18 we have recently successfully developed 2-(4H-benzo [d][1,3]oxazin-4-yl)acrylates as versatile building blocks 19 and realized organocatalytic enantioselective cycloadditions of these synthons with isocyanates, 20a 2-[aryl(tosyli mino)methyl]acrylates, 20b and 2,4-dihydro-3H-pyrazol-3-ones, 20c respectively.…”