Reaction of Nitrogen‐Radicals with Organometallics Under Ni‐Catalysis: N‐Arylations and Amino‐Functionalization Cascades
作者:Lucrezia Angelini、Jacob Davies、Marco Simonetti、Laia Malet Sanz、Nadeem S. Sheikh、Daniele Leonori
DOI:10.1002/anie.201900510
日期:2019.4
the generation of nitrogen‐radicals by ground‐state single electron transfer with organyl–NiI species. Depending on the philicity of the N‐radical, two types of processes have been developed. In the case of nucleophilic aminyl radicals direct N‐arylation with aryl organozinc, organoboron, and organosilicon reagents was achieved. In the case of electrophilic amidyl radicals, cascade processes involving
作者:Fumihiko Toriyama、Josep Cornella、Laurin Wimmer、Tie-Gen Chen、Darryl D. Dixon、Gardner Creech、Phil S. Baran
DOI:10.1021/jacs.6b07172
日期:2016.9.7
single electron transfer using Ni and Fe catalyst systems have been studied extensively, and separately, for decades. Here we demonstrate the first couplings of redox-active esters (both isolated and derived in situ from carboxylic acids) with organozinc and organomagnesium species using an Fe-based catalyst system originally developed for alkyl halides. This work is placed in context by showing a direct
几十年来,基于单电子转移使用 Ni 和 Fe 催化剂体系的烷基卤化物和有机金属物种的交叉偶联已被广泛且分别地研究。在这里,我们展示了氧化还原活性酯(从羧酸中分离和原位衍生)与有机锌和有机镁物种的首次偶联,使用最初为烷基卤化物开发的 Fe 基催化剂体系。这项工作通过展示与 Ni 催化剂的直接比较来放置在上下文中,涉及超过 40 个示例,涵盖一系列初级、二级和三级底物。这种新的 C-C 耦合具有可扩展性和可持续性,并且在某些情况下比其基于 Ni 的耦合表现出许多明显的优势。
A general alkyl-alkyl cross-coupling enabled by redox-active esters and alkylzinc reagents
作者:Tian Qin、Josep Cornella、Chao Li、Lara R. Malins、Jacob T. Edwards、Shuhei Kawamura、Brad D. Maxwell、Martin D. Eastgate、Phil S. Baran
DOI:10.1126/science.aaf6123
日期:2016.5.13
carbon-carbon bonds are often the hardest to make. Most reactions owe their efficiency to neighboring double bonds or oxygen and nitrogen atoms that linger in the products. Qin et al. now present a broadlyapplicableprotocol for making C-C bonds in the absence of such surrounding help. The nickel-catalyzed process couples a zinc-activated carbon center to an ester that's poised to lose CO2. The ready availability
<i>N</i>-Hydroxyphthalimidyl diazoacetate (NHPI-DA): a modular methylene linchpin for the C–H alkylation of indoles
作者:Rajdip Chowdhury、Abraham Mendoza
DOI:10.1039/d1cc01026c
日期:——
The insertion of conventional diazocompounds into indoles are still limited by the custom carbene precursors, catalysts and manipulation of the products required. Herein, we address these shortcomings with a redox-active carbene precursor (NHPI-DA).
alkylation, arylation, vinylation and alkynylation of nitriles is presented. The methodology uses electron-poor O-Ar cyclic oximes and organozincs as coupling partners. This redox process proceeds through the generation of an iminyl radical and its following ring-openingreaction.