A copper-catalyzed [4 + 1] annulation between α-hydroxy ketones and nitriles has been developed. The reaction provides a facile and efficient method for the construction of a wide range of highlysubstituted 3(2H)-furanones, a class of important compounds known to be associated with several biological activities.
α-Hydroxy Ketones as Masked Ester Donors in Brønsted Base Catalyzed Conjugate Additions to Nitroalkenes
作者:Iurre Olaizola、Teresa E. Campano、Igor Iriarte、Silvia Vera、Antonia Mielgo、Jesús M. García、José M. Odriozola、Mikel Oiarbide、Claudio Palomo
DOI:10.1002/chem.201705968
日期:2018.3.12
catalyst‐controlled enantioselective direct addition reaction of enolizable esters and related carboxylic acid derivatives to π electrophiles remains a difficult synthetic transformation. In this study, the suitability of α‐hydroxy ketones as ester equivalents capable of being activated by bifunctional Brønsted base catalysts in the context of conjugateaddition reactions to nitroolefins is demonstrated
Base-promoted annulation of α-hydroxy ketones and dimethyl but-2-ynedioate: straightforward access to pyrano[4,3-a]quinolizine-1,4,6(2H)-triones and 2H-pyran-2,5(6H)-diones
A novel and efficientcascadeannulation of tertiary α-hydroxy ketones and dimethyl but-2-ynedioate is reported. The reaction, which only requires a base as the promoter, provides a straightforward access to polysubstituted pyrano[4,3-a]quinolizine-1,4,6(2H)-triones and 2H-pyran-2,5(6H)-diones under very mild reactionconditions.
新型和有效的级联环的叔α-羟基酮和2-丁炔基二甲基二甲酸酯。该反应只需要一个碱作为促进剂,就可以直接获得多取代的吡喃并[4,3- a ]喹诺嗪-1,4,6 (2 H)-三酮和2 H-吡喃-2,5(6)H)-二酮在非常温和的反应条件下。