Forging Fluorine-Containing Quaternary Stereocenters by a Light-Driven Organocatalytic Aldol Desymmetrization Process
作者:Sara Cuadros、Luca Dell'Amico、Paolo Melchiorre
DOI:10.1002/anie.201706763
日期:2017.9.18
2-fluoro-substituted cyclopentane-1,3-diketones (1) leads to the stereoselective construction of valuable fluorine-containing quaternary stereocenters. The chemistry exploits the ability of a readily available amido-thiourea catalyst to selectively activate one of the enantiotopic carbonyl groups within 1 and promote an intermolecular aldol reaction of hydroxy-o-quinodimethanes, which are photochemically
Construction of Complex 1,3-Cyclohexadienes via Phosphine-Catalyzed (4 + 2) Annulations of δ-Acetoxy Allenoates and Ketones
作者:Yuwen Zhang、Xiaofeng Tong
DOI:10.1021/acs.orglett.7b02787
日期:2017.10.6
The phosphine-catalyzed substrate-dependent (4 + 2) annulations of δ-acetoxy allenoates with ketones is described. Allenoates 1 with an alkyl substituent at δC are able to react with cyclic 1,3-diketones 2, wherein the δC is attacked by the methenyl carbon of 2 while the αC attacks the ketone of 2. Allenoates 5 with an aryl group at δC is poised to react with cyclic β-carbonyl amides 6, in which the