The first oxidative C(sp3)–H phosphonylation of tertiary aliphatic amines has been developed. The use of cobalt acetate as a catalyst, N-hydroxyphthalimide as a cocatalyst, and air as an oxidant enabled the conversion of tertiary aromatic and aliphatic amines into α-aminophosphonates in moderate to excellent yields under mild conditions via a cross dehydrogenative couplingreaction.
The various α-aminophosphonates have been prepared from tertiary aromatic and aliphatic amines with P(O)H compounds via a tert-butyl hydroperoxide mediated cross-dehydrogenativecouplingreaction, eliminating the need for transition-metal catalysts. The oxidation of tertiary amine by tert-butyl hydroperoxide generates an iminium cation intermediate. A further addition of P(O)H compound to iminium cation
Dual catalysis: combining photoredox and Lewis base catalysis for direct Mannich reactions
作者:Magnus Rueping、Carlos Vila、René M. Koenigs、Konstantin Poscharny、David C. Fabry
DOI:10.1039/c0cc04539j
日期:——
A dual catalytic system combining photoredox and Lewis base catalysis has been developed. By the appropriate choice of light source and catalyst, the photoredox cycle can be optimally modulated to match the base catalyzed reaction cycle to provide the corresponding products under mild reaction conditions.
Potassium Alkylpentafluorosilicates, Primary Alkyl Radical Precursors in the C-1 Alkylation of Tetrahydroisoquinolines
作者:Teng Wang、Dong-Hui Wang
DOI:10.1021/acs.orglett.9b01124
日期:2019.6.7
alkylpentafluorosilicates (RSiF5K2) are efficient primary alkyl radical precursors for selective C(sp3)–C(sp3) bond-forming reactions. RSiF5K2 reagents are white, free-flowing solids and are moisture and air stable. This class of reagents enables the direct C-1 alkylation of tetrahydroisoquinolines under mild conditions via single-electron transfer. The broad substrate scope of both alkylpentafluorosilicates and
在这项研究中,我们证明了烷基五氟硅酸钾(RSiF 5 K 2)是选择性C(sp 3)–C(sp 3)键形成反应的有效伯烷基自由基前体。RSiF 5 K 2试剂是白色的,可自由流动的固体,对湿气和空气稳定。这类试剂可在温和条件下通过单电子转移将四氢异喹啉直接C-1烷基化。在该转化中,烷基五氟硅酸盐和四氢异喹啉都具有宽泛的底物范围。自由基清除剂和EPR捕获实验均表明,主要自由基是由RSiF 5 K 2的氧化产生的。提出了一种机制,该机制涉及将烷基自由基加到亚胺盐中,然后用胺还原。
An oxidant- and catalyst-free electrooxidative cross-coupling approach to 3-tetrahydroisoquinoline substituted coumarins
g (CDC) reaction between N-aryl-tetrahydroisoquinolines and 4-hydroxycoumarins has been realized. This protocol provides a green, mild and fast method to construct 3-tetrahydroisoquinoline substitutedcoumarins in the absence of any catalysts and exogenous oxidants. A variety of N-aryl-tetrahydroisoquinolines and 4-hydroxycoumarins are compatible with this transformation to give the corresponding products