Photochemical Decarboxylative C(sp<sup>3</sup>)–X Coupling Facilitated by Weak Interaction of N-Heterocyclic Carbene
作者:Kun-Quan Chen、Zhi-Xiang Wang、Xiang-Yu Chen
DOI:10.1021/acs.orglett.0c03006
日期:2020.10.16
still in its infancy. We demonstrate herein transition-metal-free decarboxylative C(sp3)–X bond formation enabled by the photochemical activity of the NHPI ester–NaI–NHC complex, giving primary C(sp3)–(N)phth, secondary C(sp3)–I, or tertiary C(sp3)–(meta C)phth coupling products. The primary C(sp3)–(N)phth coupling offers convenient access to primary amines.
Herein, we report the first example of group transfer radical addition of O-vinylhydroxylamine derivatives onto unactivatedalkenes. By utilizing O-vinylhydroxylamine derivatives as both the N- and C-donors, this reaction enables intermolecular carboamination of unactivatedalkenes in an atom economical fashion. As the process is initiated through N-radical addition followed by C-transfer, linear carboamination
在此,我们报告了第一个将 O-乙烯基羟胺衍生物基团转移自由基加成到未活化烯烃上的例子。通过使用 O-乙烯基羟胺衍生物作为 N 和 C 供体,该反应能够以原子经济的方式对未活化的烯烃进行分子间碳胺化。由于该过程是通过 N-自由基加成和 C-转移引发的,因此提供了线性碳胺化产物。这与烯烃的经典自由基碳官能化不同,后者通常有利于支链产物,因为它是由 C-自由基加成引发的。
Nucleophilic and Radical Heptafluoroisopropoxylation with Redox‐Active Reagents
作者:Chao‐Lai Tong、Xiu‐Hua Xu、Feng‐Ling Qing
DOI:10.1002/anie.202109572
日期:2021.10.11
heptafluoroisopropoxylation reactions through the invention of a series of redox-active N-OCF(CF3)2 reagents. These reagents were readily prepared from the oxidative heptafluoroisopropylation of hydroxylamines with AgCF(CF3)2. The substitutions on the nitrogen atom significantly affected the properties and reactivities of N-OCF(CF3)2 reagents. Accordingly, two types of N-OCF(CF3)2 reagents including N-OCF(CF3)2
Electrochemical Oxidative Difunctionalization of Alkenes to Access α-Oxygenated Ketones
作者:Changhui Dai、Yijie Shen、Yifan Wei、Ping Liu、Peipei Sun
DOI:10.1021/acs.joc.1c01831
日期:2021.10.1
Dioxygenation of alkenes was developed by the combination of electrochemical synthesis and aerobic oxidation, leading to easy accessibility of α-oxygenated ketones in an eco-friendly fashion. Using air as the oxygen source and the absence of transition metals were the critical features of this protocol. A wide range of alkenes and N-hydroxyimides were found to be compatible and provided α-oxygenated
phosphine–nickel complex and an axially chiral sodium dicarboxylate has been developed. The transformation features mild reaction conditions, a broad substrate scope, and excellent functional group tolerance, offering an efficient approach to an array of enantioenriched O-propargyl hydroxylamines. Mechanistic studies support the presumed role of the chiral carboxylate as a counterion for nickel catalysis enabling
已经开发了通过结合膦-镍络合物和轴向手性二羧酸钠催化的高度对映选择性的 O-炔丙基化。该转化具有温和的反应条件、广泛的底物范围和出色的官能团耐受性,为一系列富含对映体的O-炔丙基羟胺提供了一种有效的方法。机理研究支持手性羧酸盐作为镍催化的抗衡离子的假定作用,从而能够发现高度立体选择性的转化。该反应的威力通过其在强效萤火虫萤光素酶抑制剂和 ( S )-二氢yashabushiketol 的不对称全合成中的应用来说明。