Catalytic Asymmetric Addition of Diorganozinc Reagents to Pyrazole‐4,5‐Diones and Indoline‐2,3‐Diones

Abstract

The catalytic enantioselective diorganozinc additions to cyclic diketones including pyrazolin‐4,5‐diones and isatins have been developed. In the presence of morpholine‐containing chiral amino alcohol ligand, the corresponding chiral cyclic tertiary alcohols were produced in good to excellent yields (up to 97 %) and enantioselectivities (up to 95 % ee). The notable feature of this protocol includes its mild reaction conditions, Lewis acid additives free and broad functional group tolerance.

Recent advances in the applications of pyrazolone derivatives in enantioselective synthesis

“…Later, in 2021, using the chiral amino alcohol ligand L16, the enantioselective addition of diorganozinc reagents 168 to pyrazole-4,5-diones 4a was reported by Chen and co-workers (Scheme 36b). 68 The desired pyrazolone derivatives 169 were obtained in good yields and with good enantioselectivities. Besides simple addition, the (3 + 2) annulation and cycloaddition of pyrazole-4,5-diones provided an avenue to oxaspirocyclic pyrazolones.…”

Recent advances in the asymmetric catalytic construction of oxa-quaternary carbon centers

“…11 In 2021, Chen and coworkers reported the asymmetric additions of diorganozinc reagents to cyclic ketones including pyrazole-4,5-diones and substituted isatins in the presence of a chiral amino alcohol ligand under mild conditions (Scheme 4). 12 A wide range of highly functionalized tertiary alcohol products with pyrazolone and 2-oxindole motifs could be obtained in excellent yields (up to 97% yield) with high to excellent enantioselectivities (up to 95% ee).…”

Organocatalytic Asymmetric Morita–Baylis–Hillman Reaction of Isatins with Vinyl Sulfones

“…Based on the research background and our continuous work on the asymmetric synthesis of 3-hydroxyoxindoles, we accomplish the organocatalytic asymmetric MBH reactions of isatins with vinyl sulfones as the activated alkenes, providing facile access to chiral sulfone-containing 3-hydroxyoxindoles with an alkene functional group (Scheme b).…”