α-Cyanation of Aromatic Tertiary Amines using Ferricyanide as a Non-Toxic Cyanide Source
作者:Alexander M. Nauth、Nicola Otto、Till Opatz
DOI:10.1002/adsc.201500698
日期:2015.11.16
reaction of aromatictertiaryamines with potassium ferricyanide directly provides the useful α-amino nitriles. The inexpensive iron complex functions both as an oxidant and as a cyanidesource. The presence of molecular oxygen speeds up the reaction which can be performed in aqueous tert-butanol or even in ethanol-based mixtures like Tequila. While amine cyanations usually employ highly toxic cyanide sources
Efficient and General Aerobic Oxidative Cross-Coupling of THIQs with Organozinc Reagents Catalyzed by CuCl<sub>2</sub>: Proof of a Radical Intermediate
general new method for the highly concise synthesis of C-1-alkylated tetrahydroisoquinolines (THIQ) is reported. The CuCl2-catalyzed procedure is based on a coupling of nonfunctionalized THIQs with organozincreagents under aerobic conditions. It proceeds in high yields and is broadly applicable to a wide range of substrates. It relies on a regioselective sp3 C–H bond activation allowing for an sp3–sp3
Radical alkylation of C(sp<sup>3</sup>)–H bonds with diacyl peroxides under catalyst-free conditions
作者:Hao Tian、Wentao Xu、Yuxiu Liu、Qingmin Wang
DOI:10.1039/c9cc08056b
日期:——
Herein, we describe a protocol for alkylation reactions of C(sp3)–H bonds with diacylperoxides by means of a process involving cross-coupling between an alkyl radical and an α-aminoalkyl radical. The mild, catalyst- and additive-free conditions make this protocol superior to previously reported C(sp3)–H alkylation strategies. The protocol was applied to 1,2,3,4-tetrahydroisoquinolines and a tetrahydro-β-carboline
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。
Investigations of the Copper-Catalyzed Oxidative Cross-Coupling of Tetrahydroisoquinolines with Diethylzinc by a Combination of Mass Spectrometric and Electrochemical Methods
作者:J. Alexander Willms、Hermann Gleich、Michael Schrempp、Dirk Menche、Marianne Engeser
DOI:10.1002/chem.201704914
日期:2018.2.21
consistently revealed strong influences of the N‐substituent of the THIQ derivative and its oxidation stability with respect to CuCl2. The results may help to expand the synthetic scope of the reaction, while also further establishing EC‐MS as a valuable technique for linking mass spectrometry with cyclic voltammetry in mechanistic studies of organic redox reactions.