Organocatalytic Asymmetric Synthesis of α-Oxetanyl and α-Azetidinyl Tertiary Alkyl Fluorides and Chlorides
作者:Ransheng Ding、Christian Wolf
DOI:10.1021/acs.orglett.8b00039
日期:2018.2.2
Asymmetric thiourea and squaramide catalysis provides access to synthetically versatile α-oxetanyl and α-azetidinyl alkyl halides exhibiting a tetrasubstituted chiral carbon center with high yields and enantioselectivities. The products are readily transformed with negligible erosion of enantiopurity and excellent diastereoselectivity to a diverse group of multifunctional compounds including fluorooxindoles
Enantioselective conjugate addition of 3-fluoro-oxindoles to vinyl sulfone: an organocatalytic access to chiral 3-fluoro-3-substituted oxindoles
作者:Xiaowei Dou、Yixin Lu
DOI:10.1039/c3ob41267a
日期:——
An organocatalytic conjugate addition of prochiral 3-fluorinated oxindoles to vinyl sulfones was described for the first time. In the presence of bifunctional tertiary amine–thiourea catalysts, 3-fluoro-3-substituted oxindole adducts were obtained in excellent yields and with high enantiomeric excesses.
A catalytic regioselective addition reaction of oxindoles with ynals is developed. Allene-containing derivatives bearing various substituents and substitution patterns are afforded as the products in generally moderate to good yields with moderate diastereoselectivities. Several of allenes obtained from this protocol are valuable in the development of novel bactericides for plant protection.
Organocatalytic Asymmetric Conjugate Addition of Fluorooxindoles to Quinone Methides
作者:Maria Bouda、Jeffery A. Bertke、Christian Wolf
DOI:10.1021/acs.joc.4c00062
日期:2024.5.3
Fluorooxindoles undergo asymmetricMichaeladdition to para-quinone methides under phase-transfer conditions with 10 mol% of a readily available cinchona alkaloid ammonium catalyst. This reaction affords sterically encumbered, multifunctional fluorinated organic compounds displaying two adjacent chirality centers with high yields, ee’s and dr’s.