01711nas a2200193   4500008004100000245015800041210007000199260000800269300001600277490000700293520094900300100002301249700001701272700001701289700003101306700002701337700002201364856013101386       2017                        eng d00aEnantioselective synthesis of spiro γ-butyrolactones by N-heterocyclic carbene (NHC)-catalyzed formal [3+2] annulation of enals with 3-hydroxy oxindoles0 aEnantioselective synthesis of spiro γbutyrolactones by Nheterocy  cFEB  a2013 - 20190 v163 aThe N-heterocyclic carbene (NHC)-catalyzed enantioselective formal [3 + 2] annulation of α,β-unsaturated aldehydes with 3-hydroxy oxindoles is presented. Under oxidative conditions using the bisquinone oxidant, the reaction resulted in the synthesis of spiro γ-butyrolactones in moderate to good yields, enantioselectivity and diastereoselectivity. The reaction likely proceeds via the generation of the NHC-bound α,β-unsaturated acylazolium intermediate from enals, which was intercepted by the dioxindoles in a formal [3 + 2] pathway to form the spirocyclic compounds. However, a deeper mechanistic investigation revealed that the reaction can also proceed via the homoenolate intermediate. In this case, the dioxindole was oxidized to the corresponding isatin derivative using traces of air under basic conditions, and was intercepted with the NHC-bound homoenolate intermediate in a formal [3 + 2] pathway to afford the spiro compound.1 aMukherjee, Subrata1 aJoseph, Sumi1 aBhunia, Anup1 aGonnade, Rajesh, Ghanshyam1 aReddy, Santhi, Vardhan1 aBiju, Akkattu, T.  uhttps://library.ncl.res.in/content/enantioselective-synthesis-spiro-%CE%B3-butyrolactones-n-heterocyclic-carbene-nhc-catalyzed01160nas a2200181   4500008004100000245011000041210006900151260000800220300001600228490000700244520048800251100002900739700001800768700001700786700002700803700002200830856012600852       2017                        eng d00aFacile synthesis of N-acyl 2-aminobenzothiazoles by NHC-catalyzed direct oxidative amidation of aldehydes0 aFacile synthesis of Nacyl 2aminobenzothiazoles by NHCcatalyzed d  cJAN  a1478 - 14810 v533 aA mild, general, and high yielding synthesis of N-acyl 2-aminobenzothiazoles has been demonstrated by N-heterocyclic carbene (NHC)-organocatalyzed direct amidation of aldehydes with 2-aminobenzothiazoles proceeding via acyl azolium intermediates. The carbene generated from the triazolium salt under oxidative conditions was the key for the success of this reaction. The method was subsequently applied to the synthesis of various biologically important N-acyl 2-aminobenzothiazoles.1 aPremaletha, Sethulekshmi1 aGhosh, Arghya1 aJoseph, Sumi1 aReddy, Santhi, Vardhan1 aBiju, Akkattu, T.  uhttps://library.ncl.res.in/content/facile-synthesis-n-acyl-2-aminobenzothiazoles-nhc-catalyzed-direct-oxidative-amidation