Reported herein is a novel visible‐light photoredox system with Pd(PPh3)4 as the sole catalyst for the realization of the first direct cross‐coupling of C(sp3)−H bonds in N‐aryl tetrahydroisoquinolines with unactivated alkyl bromides. Moreover, intra‐ and intermolecular alkylations of heteroarenes were also developed under mild reaction conditions. A variety of tertiary, secondary, and primary alkyl
Dual-catalyst engineered porous organic framework for visible-light triggered, metal-free and aerobic sp3 C H activation in highly synergistic and recyclable fashion
作者:Gaurav Kumar、Soumya Ranjan Dash、Subhadip Neogi
DOI:10.1016/j.jcat.2020.12.013
日期:2021.2
visible-light triggered oxidativeMannichreaction to produce biorelevant heterocycle β-amino ketone in excellent yield at room temperature, using oxygen as clean and selective oxidant. Importantly, activity of this bi-functionalized catalyst compares favorably well to individual homogeneous counterparts. The covalently modified framework demonstrates economic viability via gram-scale synthesis besides
光氧化还原和有机催化代表了新型碳-碳键的强大构建工具,在温和的条件下,两种方法在单个可回收平台上的精细融合可在环境下产生协同和生态友好的反应。旨在基于烯胺的光氧化还原催化原子经济和无金属的sp 3 C H活化,设计了一种基于酰胺的二维(2D)多孔有机骨架(POF)。下垂的NH 2各组明智地锚定有两个催化站。玫瑰孟加拉和L-脯氨酸,通过逐步改变固相肽合成。双催化剂工程化的POF代表一种完全有机的材料,它可以在室温下协同地执行可见光触发的氧化曼尼希反应,以氧气的清洁和选择性氧化剂的优异收率生产生物相关的杂环β-氨基酮。重要的是,这种双官能化催化剂的活性与单独的均相对应物相比非常好。共价修饰的框架除具有令人称赞的可重复使用性外,还通过克级合成证明了经济可行性,并被证明对19种底物有效。根据实验和理论研究,详细说明了从主体聚合物到底物的有效能量转移的光催化路径,这为光有机结合机理提供了概念验证。除
Enantioselective Aerobic Oxidative C(sp<sup>3</sup>)–H Olefination of Amines via Cooperative Photoredox and Asymmetric Catalysis
A cooperative photoredox and asymmetriccatalysis for the enantioselective aerobic oxidative C(sp3)–H olefination of tetrahydro-β-carbolines (THCs) is reported. This method, which is also effective for tetrahydroisoquinolines (THIQs), features a triple-catalyst strategy, involving a dicyanopyrazine-derived chromophore (DPZ) as the metal-free photoredox catalyst, a chiral Lewis base catalyst, and an
A visible‐light photoredox‐catalyzed reaction of tetrahydroisoquinolines with β‐fluorinated gem‐diols results in the formation of C1‐monofluoromethylated tetrahydroisoquinolines via C(sp3)Hbondactivation. This protocol provides a new method to introduce a CF group with stable, easily‐prepared monofluorinated gem‐diol as CF source. A mechanistic investigation is presented based on control experiments
Photoredox/cobaloxime co-catalyzed allylation of amines and sulfonyl hydrazines with olefins to access α-allylic amines and allylic sulfones
作者:Hui Xu、Hong Zhang、Qing-Xiao Tong、Jian-Ji Zhong
DOI:10.1039/d1ob01307f
日期:——
reported a dual-catalytic platform for the allylation of amines and sulfonyl hydrazines with olefins to selectively access α-allylic amines and allylic sulfones in good yields by combining photoredox catalysis and cobaloxime catalysis. This strategy avoided the use of a stoichiometric amount of terminal oxidant and the use of pre-functionalized allylic precursors, representing a green and ideal atom- & step-economical