A Facile Approach for the Asymmetric Synthesis of Oxindoles with a 3-Sulfenyl-Substituted Quaternary Stereocenter
摘要:
With the employment of a threonine-incorporating multifunctional catalyst 9, Michael addition of 3-sulfenyloxindoles to nitroolefins proceeded stereoselectively, leading to the formation of oxindoles with a 3-sulfenyl-substituted quaternary center in excellent yields, and with high diastereoselectivities and excellent enantioselectivities.
A Mild and Direct C(sp<sub>3</sub>)–S Cross-Coupling of Oxindoles with Thiols: Synthesis of Unsymmetrical 3-Thiooxindoles
作者:Hui Qin、Qi Li、Jian Xu、Jie Zhang、Wei Qu、Wenyuan Liu、Feng Feng、Haopeng Sun
DOI:10.1021/acs.joc.9b02205
日期:2019.11.1
Herein, an operationally simple and mild strategy to construct sulfenation of oxindoles with a series of thiols in the absence of transition metals was developed. This methodology provides an efficient way to directly form a C-S bond at the C-3 position of oxindoles under mild reaction conditions with a cheap and common solvent and base in moderate to good yields.
Highly enantioselective Michael addition of 3-arylthio- and 3-alkylthiooxindoles to nitroolefins catalyzed by a simple cinchona alkaloid derived phosphoramide
A new cinchona alkaloid derived bifunctional tertiary amine-phosphoramide C1e is identified as a highly enantioselective catalyst for Michael addition of both unprotected 3-arylthio- and 3-alkylthiooxindoles to nitroolefins. The phosphoramide moiety of C1e plays an indispensable role in this reaction.
We report the first example of highly enantioselective synthesis of structurally diverse chiral dithioketalsviaasymmetric sulfenylation of various types of S-based nucleophiles, catalyzed by a cheap cinchona alkaloid derivative, dihydroquinine.
We report the first organocatalytic asymmetric synthesis of 3,3-disubstituted oxindoles featuring two heteroatoms at the C3 position. Importantly, 3-thiooxindoles and 3-alkoxyoxindoles are demonstrated to be reactive nucleophiles for the development of catalytic asymmetric reactions for the first time.