Alkynyl Acylammoniums as Electrophilic 3C Synthons in a Formal [3 + 3] Annulation: Access to Functionalized 4<i>H</i>-Pyran-4-ones
作者:Shuding Dong、Chao Fang、Weifang Tang、Tao Lu、Ding Du
DOI:10.1021/acs.orglett.6b01891
日期:2016.8.5
acylammoniums generated in situ from alkynyl acids are first used as electrophilic 3C synthons in a formal [3 + 3] annulation with 1,3-dicarbonyl compounds for regioselective synthesis of functionalized 4H-pyran-4-ones via a 4-(dimethylamino)pyridine/Lewis acid dual-activation strategy. This protocol paves the way for further investigation of alkynyl acylammoniums as 3C synthons for construction of diverse heterocyclic
Ruthenium-Catalyzed Dimerization of Propiolates: A Simple Route to α-Pyrones
作者:Rajendran Manikandan、Masilamani Jeganmohan
DOI:10.1021/ol4035929
日期:2014.2.7
A ruthenium-catalyzed regioselective intermolecular multistep homo- and heterodimerization of substituted propiolates providing α-pyrone-5-carboxylates and α-pyrone-6-carboxylates is described. The synthetic utilities of α-pyrone derivatives are shown. The proposed mechanism is strongly supported by experimental evidence.