photoactivation and asymmetric Pd catalysis. The key to the success of this method is the enantioselective trapping of Pd-containing, 1,5-dipolar intermediates by ketenes, a class of reactive C2 synthons, which were generated in an in situ and traceless manner under visible light irradiation. Through this trapping, a variety of 7-membered lactones bearing challenging chiral quaternary stereocenters can be accessed
Carbocation Lewis Acid TrBF<sub>4</sub>-Catalyzed 1,2-Hydride Migration: Approaches to (<i>Z</i>)-α,β-Unsaturated Esters and α-Branched β-Ketocarbonyls
作者:Wansong Shang、Depeng Duan、Yongjun Liu、Jian Lv
DOI:10.1021/acs.orglett.9b03005
日期:2019.10.4
CarbocationLewisacid TrBF4-catalyzed 1,2-hydride migration of α-alkyldiazoacetates themselves or in situ-generated cross-coupling adducts of aldehydes and α-alkyldiazoacetates has been developed, affording (Z)-α,β-unsaturated esters and α-branched β-ketocarbonyls, respectively, in good yields and with high regioselectivities.
Visible-Light-Induced Catalysis: A Regioselectivity Switch between [2+1] and [2+2] Cycloaddition of Diazocarbonyls with Olefins
作者:Jian Lv、Huixin Qiu、Lirong Wen
DOI:10.1055/a-1786-6496
日期:2022.9
Visible-light-promoted [2+1] and [2+2] cycloadditionreactions of diazocarbonyls with olefins have been developed, affording functionalized cyclopropanes and cyclobutanes, respectively. In visible-light catalysis of Ir(ppy)3, a simple addition of Rh2(OAc)4 switches the regioselectivity from [2+1] to [2+2] cycloaddition with good reactivity and high regioselectivity.