N-Heterocyclic Carbene-Catalyzed <i>in situ</i>
Activation of Alkynyl Acids for C−S Bond Formation: Access to Imidazo[2,1-<i>b</i>
][1,3]thiazinones
作者:Kewen Sun、Shiyi Jin、Jindong Zhu、Xinmiao Zhang、Maoyu Gao、Wanqi Zhang、Tao Lu、Ding Du
DOI:10.1002/adsc.201800857
日期:2018.12.3
Alkynylacids are first utilized as alkynyl acylazolium precursors through an in situactivation strategy for the efficient construction of carbon‐sulfur bond in a formal [3+3] annulation. This protocol offers a direct and rapid pathway for the synthesis of imidazo[2,1‐b][1,3]thiazinone skeleton, a useful heterocyclic class frequently found in many bioactive compounds. This reaction also has the advantages
炔酸首先通过原位活化策略用作炔基酰基la唑前体,以便在正式的[3 + 3]环空中有效构建碳硫键。该方案为合成咪唑并[2,1– b ] [1,3]噻嗪酮骨架提供了直接而快速的途径,该骨架是在许多生物活性化合物中经常发现的有用的杂环类。该反应还具有可扩展性,易于获得的材料以及在露天中易于操作的优点。
Palladium-Catalyzed Cyclocarbonylation Approach to Thiadiazafluorenones: A Correction
3-methyl isomers, as unequivocally established by XRD analysis of a representative product. A correction is therefore provided here in order to rectify the previous erroneous assignment of the position of the methyl group. Moreover, the process has been generalized to substrates bearing an internal triple bond, which lead to 3-alkyl-2-methyl-1-thia-4a,9-diazafluoren-4-ones, whose structure was confirmed by