Organocatalytic Enantioselective Stereoablative Hydroxylation of 3-Halooxindoles: An Effective Method for the Construction of Enantioenriched 3-Substituted 3-Hydroxy-2-Oxindoles
3‐Substitutedoxindoles as electrophilic partners: An unprecedented method for the construction of hydroxylated 3‐substitutedoxindoles in high yields and excellent enantioselectivities through stereoablative hydroxylation of 3‐halooxindoles with an organocatalyst has been developed. This process not only differs from the common convention of using 3‐substitutedoxindoles as nucleophiles, but also
A Facile Method for the Synthesis of 3-Alkyloxindole
作者:Tai-Ping Du、Gang-Guo Zhu、Jian Zhou
DOI:10.2174/157017812800167420
日期:2012.3.1
Benzylamine in combination with acetic acid was identified as a powerful catalyst for the condensation of oxindole with aldehydes, acetone or cyclic ketones. A variety of 3-alkyloxindoles could be readily prepared in 10 mmol scale via the sequential benzylamine acetate catalyzed condensation of oxindoles with aldehydes (or ketones) and conjugate reduction by NaBH4.
Organocatalytic asymmetric Michael addition between 3-subsituted oxindoles and enals catalyzed by camphor sulfonyl hydrazine
作者:Wen-Fu Cheng、Ling-Yan Chen、Fang-Fang Xu、Wei-Yu Lin、Xinfeng Ren、Ya Li
DOI:10.1039/c8ob02934b
日期:——
Organocatalyticasymmetric Michael addition between 3-substituted oxindoles and enals catalyzed by chiral camphor sulfonyl hydrazines (CaSHs) has been developed. A wide range of 3-substituted oxindoles and enals were successfully used, giving the corresponding 3,3-disubstituted oxindoles containing vicinal stereogenic carbon centers in good yields with good to excellent enantioselectivities and moderate
Catalytic asymmetric α‐arylation of N‐unprotected 3‐substituted oxindoles with diaryliodoniumsalts has been realized by a chiral Lewis acid promoted electrophilic addition and aryl‐rearrangement process. Single C3‐arylated products containing a quaternary carbon center were generated in high enantioselectivity and reactivity.
The highly Z‐selective asymmetric conjugateaddition of 3‐substituted oxindoles to alkynyl carbonyl compounds has been developed by using scandium complexes of chiral N,N′‐dioxides under mild conditions. The thermodynamically unstable Z‐olefin derivatives were obtained in excellent yields and high enantiomeric and geometric control. The catalyst was also found to be effective in the asymmetric acetylenic