inexpensive, nontoxic manganese catalyst enabled unprecedented redox‐neutral carbonylative annulations under ambient pressure. The manganese catalyst outperformed all other typically used base and precious‐metal catalysts. The outstanding versatility of the manganese catalysis manifold was reflected by ample substrate scope, setting the stage for effective late‐stage manipulations under racemization‐free
The Pd(ii)-catalyzed pyridine-directed carbonylative cycloamidation of ketoimines has provided an efficient protocol for assembly of pyrido[1,2-a]pyrimidin-4-ones.
Metal free C-3 chalcogenation (sulfenylation and selenylation) of 4<i>H</i>-pyrido[1,2-<i>a</i>]pyrimidin-4-ones
作者:Prasanjit Ghosh、Gautam Chhetri、Sajal Das
DOI:10.1039/d1ra00834j
日期:——
An expeditious metal free C-3 chalcogenation of 4H-pyrido[1,2-a]pyrimidin-4-one has been devised to synthesize diversely orchestrated 3-ArS/ArSe derivatives in high yields (up to 95%). This operationally simple reaction proceeds under mild reaction conditions, can be executed in gram scale, and also highlights broad functional group tolerance. Preliminary experimental investigation suggests a radical
设计了 4 H -pyrido[1,2- a ]pyrimidin-4-one 的快速无金属 C-3 硫属化反应,以高产率(高达 95%)合成多种精心设计的 3-ArS/ArSe 衍生物。这种操作简单的反应在温和的反应条件下进行,可以以克级进行,并且还突出了广泛的官能团耐受性。初步实验研究表明了这些转变的根本机制途径。
Transition-metal-free lactamization of C(sp<sup>3</sup>)–H bonds with CO<sub>2</sub>: facile generation of pyrido[1,2-<i>a</i>]pyrimidin-4-ones
A novel carbonylation of C(sp3)–H bonds in pyridylamines with one atmosphere of CO2 is reported to synthesize important pyrimidinones in good yields. This transition-metal-free and redox-neutral process features the use of a nontoxic carbonyl source, broad substrate scope, good functional group tolerance, facile scalability and easy product derivatization.
Enantioselective hydrogenation of annulated arenes: controlled formation of multiple stereocenters in adjacent rings
作者:Mario P. Wiesenfeldt、Daniel Moock、Daniel Paul、Frank Glorius
DOI:10.1039/d0sc07099h
日期:——
hydrogenation of annulated arenes using 4H-pyrido[1,2-a]pyrimidinones as substrates. The method selectively generates multiple stereocenters in adjacent rings leading to architecturally complex motifs, which resemble bioactive molecules. The mechanistic study of the stereochemical outcome revealed that the catalyst is able to overcome substrate stereocontrol providing all-cis-substituted products predominantly
我们报告了一种使用 4 H-吡啶并[1,2- a ]嘧啶酮作为底物对环状芳烃进行对映选择性氢化的方法。该方法选择性地在相邻环中生成多个立体中心,从而形成结构复杂的图案,类似于生物活性分子。立体化学结果的机理研究表明,该催化剂能够克服底物立体控制,主要提供全顺式取代的产物。在顺序方案中,实现了催化剂和底物立体控制之间的匹配相互作用,这有利于非对映和对映选择性获得反式产物。