FeCl<sub>3</sub>-Assisted Niobium-Catalyzed Cycloaddition of Nitriles and Alkynes: Synthesis of Alkyl- and Arylpyrimidines Based on Independent Functions of NbCl<sub>5</sub>and FeCl<sub>3</sub>Lewis Acids
作者:Maito Fuji、Yasushi Obora
DOI:10.1021/acs.orglett.7b02708
日期:2017.10.20
NbCl5-catalyzed [2 + 2 + 2] cycloaddition of nitriles with alkynes was used to synthesize pyrimidine derivatives. In this reaction, the use of individual Lewis acids, namely NbCl5 and FeCl3, is a key strategy for achieving the reaction using a catalytic amount of NbCl5. The roles of the two Lewis acids were investigated using FT-IR spectroscopy. The results showed that NbCl5 served as an efficient
Strategy for the Synthesis of Pyrimidine Derivatives: NbCl<sub>5</sub>-Mediated Cycloaddition of Alkynes and Nitriles
作者:Yasushi Satoh、Kaoru Yasuda、Yasushi Obora
DOI:10.1021/om300669s
日期:2012.8.13
Intermolecular cycloadditions of alkynes (terminal alkynes and internal alkynes) with aryl nitriles were successfully achieved, using an NbCl5 complex, to give substituted pyrimidine derivatives in high yields with excellent chemo- and regioselectivity.
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,