Sc(OTf)<sub>3</sub>-Catalyzed Conjugate Allylation of Alkylidene Meldrum’s Acids
作者:Aaron M. Dumas、Eric Fillion
DOI:10.1021/ol9003959
日期:2009.5.7
Alkylidene Meldrum’s acids are allylated in a conjugate fashion by allyltin nucleophiles under mild Sc(OTf)3-catalyzed conditions. The addition is functional group tolerant and reactions with nonracemic alkylidenes are highlydiastereoselective. Allylation of alkylidenes derived from α-ketoesters yield all-carbon quaternary stereocenters.
Asymmetric Synthesis of Carboxylic Acid Derivatives Having an All-Carbon α-Quaternary Center through Cu-Catalyzed 1,4-Addition of Dialkylzinc Reagents to 2-Aryl Acetate Derivatives
作者:Ashraf Wilsily、Eric Fillion
DOI:10.1021/ol800923q
日期:2008.7.3
The asymmetric synthesis of carboxylicacidderivatives having an all-carbon alpha-quaternary center has been achieved via copper-catalyzed 1,4-addition of dialkylzinc reagents to aryl acetate derivatives in the presence of phosphoramidite ligand. High isolated yields and enantioselectivities were obtained. It was demonstrated that the Meldrum's acid and ester moieties present on the all-carbon quaternary
Expedient Synthesis of Complex γ-Butyrolactones from 5-(1-Arylalkylidene) Meldrum’s Acids via Sequential Conjugate Alkynylation/Ag(I)-Catalyzed Lactonization
作者:Siawash Ahmar、Eric Fillion
DOI:10.1021/ol502811j
日期:2014.11.7
The conjugate alkynylation of alkylidene Meldrums acids with alkynylalanes and alkynyl Grignards allows for the formation of propargylic all-carbon quaternary stereocenters in high yields. Ag2CO3-catalyzed intramolecular cyclization of propargylic Meldrums acid derivatives offers a two-step entry into complex gamma-alkylidene butyrolactones containing an all-carbon quaternary center at the C-4 position.
All‐Carbon Tetrasubstituted Olefins Synthesis from Diazo Compounds and Iodonium Ylides under Blue LED Irradiation
作者:Yan‐Rui Zhao、Lei Li、Guo‐Yong Xu、Jun Xuan
DOI:10.1002/adsc.202101144
日期:2022.2
tetra-substituted olefins through visible-light promoted coupling of diazo compounds with iodonium ylides was developed. A wide range of all-carbon tetra-substituted olefins was obtained in moderate to good yields. The synthetic values of the current method were further approved by the synthesis of natural isolates modified alkenes and the successful transformation of final olefins into important heterocycles