Enantioselective Synthesis of γ-Lactams by Lewis Base Catalyzed Sulfenoamidation of Alkenes
作者:Jesse L. Panger、Scott E. Denmark
DOI:10.1021/acs.orglett.9b04347
日期:2020.4.3
A method for the catalytic, enantioselective, intramolecular 1,2-sulfenoamidation of alkenes is described. Lewisbase activation of a suitable sulfur electrophile generates an enantioenriched, thiiranium ion intermediate from a β,γ-unsaturated sulfonyl carboxamide. This intermediate is subsequently intercepted by the sulfonamide nitrogen resulting in cyclization to form γ-lactams. Electron-poor alkenes
Pd-catalyzed 5-endo-trig-type cyclization of β,γ-unsaturated carbonyl compounds: an efficient ring closing reaction to give γ-butenolides and 3-pyrrolin-2-ones
作者:Gan B. Bajracharya、Priti S. Koranne、Rashid N. Nadaf、Randa Kassem Mohamed Gabr、Kazuhiro Takenaka、Shinobu Takizawa、Hiroaki Sasai
DOI:10.1039/c0cc02352c
日期:——
The 5-endo-trig-type cyclization has been performed using a Pd-bis(isoxazoline) catalyst. The present cyclization of beta,gamma-unsaturated carbonylcompounds gave gamma-butenolides and 3-pyrrolin-2-ones in good to excellent yields.