Copper(II)-Catalyzed Reactions of α-Keto Thioesters with Azides via C–C and C–S Bond Cleavages: Synthesis of <i>N</i>-Acylureas and Amides
作者:Rajib Maity、Sandip Naskar、Indrajit Das
DOI:10.1021/acs.joc.7b03054
日期:2018.2.16
Cu(II)-catalyzed reaction of α-keto thioesters with trimethylsilyl azide (TMSN3) proceeds with the transformation of the thioester group into urea through C–C and C–S bond cleavages, constituting a practical and straightforward synthesis of N-acylureas. When diphenyl phosphoryl azide (DPPA) is used instead as the azide source in an aqueous environment, primary amides are formed via substitution of
Visible-Light-Activated Divergent Reactivity of Dienones: Dimerization in Neat Conditions and Regioselective <i>E</i> to <i>Z</i> Isomerization in the Solvent
作者:Sandip Naskar、Sabyasachi Roy Chowdhury、Somrita Mondal、Dilip K. Maiti、Sabyashachi Mishra、Indrajit Das
DOI:10.1021/acs.orglett.9b00083
日期:2019.3.15
4-Dienones undergo visible-light-promoted, photocatalyst-free dimerization in neat conditions to provide cyclohexene derivatives stereoselectively through cascade rearrangement pathways, whereas regioselective E → Z isomerization of the more dienophilic doublebond takes place exclusively in nitromethane. On the basis of intermediate isolation and computational DFT studies, the dimerization reaction is proposed