Acid-controlled multicomponent selective synthesis of 2,4,6-triaryl pyridines and pyrimidines by using hexamethyldisilazane as a nitrogen source under microwave irradiation
作者:Chieh-Kai Chan、Yi-Hsiu Chung、Cheng-Chung Wang
DOI:10.1039/d2ra04739j
日期:——
protocol for the synthesis of functionalized 2,4,6-triaryl pyridines and pyrimidines was developed from commercially available aromatic ketones, aldehydes and hexamethyldisilazane (HMDS) as a nitrogen source undermicrowave irradiation. In this multicomponent synthetic route, Lewis acids play an important role in selectively synthesizing six-membered heterocycles, including pyridines (1N) and pyrimidines
Oxidative Coupling with Zr(IV) Supported by a Noninnocent Anthracene-Based Ligand: Application to the Catalytic Cotrimerization of Alkynes and Nitriles to Pyrimidines
作者:Choon Heng Low、Jeffrey N. Rosenberg、Marco A. Lopez、Theodor Agapie
DOI:10.1021/jacs.8b07418
日期:2018.9.26
We report the synthesis and reactivity of Zr complexes supported by a 9,10-anthracenediyl-linked bisphenoxide ligand, L. ZrIVLBn2 (1) undergoes facilephotolytic reduction with concomitant formation of bibenzyl and ZrIVL(THF)3 (2), which displays a two-electron reduced anthracene moiety. Leveraging ligand-stored reducing equivalents, 2 promotes the oxidative coupling of internal and terminal alkynes
我们报告了由 9,10-蒽二基连接的双酚盐配体 L. ZrIVLBn2 (1) 支持的 Zr 配合物的合成和反应性,伴随着联苄和 ZrIVL(THF)3 (2) 的形成,它经历了轻松的光解还原,显示出双电子还原蒽部分。利用配体储存的还原当量,2 促进了内部和末端炔烃与可分离的氧化锆环戊二烯配合物的氧化偶联,证明了蒽作为氧化还原储层的可逆利用。与二苯乙炔在 CO 下,按化学计量形成环戊二烯酮。2 能够从炔烃和腈催化形成嘧啶。机理研究表明,嘧啶的选择性源于氮杂锆并环戊二烯中间体的优先形成,