Tungsten-Catalyzed Transamidation of Tertiary Alkyl Amides
作者:Fang-Fang Feng、Xuan-Yu Liu、Chi Wai Cheung、Jun-An Ma
DOI:10.1021/acscatal.1c01840
日期:2021.6.18
chloride as a catalyst and chlorotrimethylsilane as an additive. The highly electrophilic and oxophilic tungsten catalyst enables the selective scission of a C–N bond of tertiary alkyl amides to effect transamidation of a myriad of structurally and electronically diverse tertiary alkyl amides and amines. Mechanistic study implies that the synergistic effect of the catalyst and the additive could pronouncedly
Thiophenol-Catalyzed Visible-Light Photoredox Decarboxylative Couplings of <i>N</i>-(Acetoxy)phthalimides
作者:Yunhe Jin、Haijun Yang、Hua Fu
DOI:10.1021/acs.orglett.6b03300
日期:2016.12.16
We have developed visible-light photoredox decarboxylative couplings of N-(acetoxy)phthalimides without an added photocatalyst in which simple and commercially available thiophenols are used as the effective organocatalysts, and 4-(trifluoromethyl)thiophenol shows optimal catalytic activity. Three representative decarboxylative examples were chosen including one amination and two C–C bond couplings
Deboronative functionalization of alkylboron species via a radical-transfer strategy
作者:Fuyang Yue、Mingxing Li、Kangkang Yang、Hongjian Song、Yuxiu Liu、Qingmin Wang
DOI:10.1039/d4sc02889a
日期:——
With advances in organoboron chemistry, boron-centered functional groups have become increasingly attractive. In particular, alkylboron species are highly versatile reagents for organic synthesis, but the direct generation of alkyl radicals from commonly used, bench-stable boron species has not been thoroughly investigated. Herein, we describe a method for activating C–B bonds by nitrogen- or oxygen-radical
随着有机硼化学的进步,以硼为中心的官能团变得越来越有吸引力。特别是,烷基硼物质是用于有机合成的高度通用的试剂,但从常用的、实验室稳定的硼物质直接生成烷基自由基尚未得到彻底研究。在此,我们描述了一种通过氮或氧自由基转移激活 C-B 键的方法,该方法适用于烷基硼酸和酯,并且可用于 Michael 加成反应和 Minisci 反应以生成烷基或芳基化产物。
Charge-directed conjugate addition reactions of silylated .alpha.,.beta.-unsaturated amidate anions
作者:Manning P. Cooke、Charles M. Pollock
DOI:10.1021/jo00078a028
日期:1993.12
A variety of N-substituted alpha-silylated-alpha,beta-unsaturated amidate anions (2) have been found to be excellent Michael acceptors in charge-directed conjugate addition reactions with Grignard and organolithium reagents. The effects of olefin substitution, Si-substitution, N-substitution, and amidate counterion have been studied. Anionic acceptors may be prepared in situ by the addition of silylated vinyllithium reagents to isocyanates and then allowed to undergo conjugate addition reactions with subsequently added nucleophiles, but it was found to be more efficient to isolate neutral acceptors and regenerate the acceptor anion through the use of excess nucleophile. Beta-Substituted acceptors were found to react only with reactive organolithium reagents while a beta,beta-disubstituted acceptor failed to undergo conjugate addition reactions. A primary amide acceptor (14d) also undergoes addition reactions with larger quantitites of nucleophiles suggesting that dianionic amidate acceptors (31) are involved. Diene acceptor 24 was found to undergo a 1,6-addition reaction with n-BuLi. Sodium and potassium amidate salts were found to be inferior to lithium and magnesium salts in addition reactions in keeping with the expectation that an increase in carbonyl-group charge burden retards conjugate reactions. Triphenylsilyl-containing acceptor 16 was found to be more reactive in reactions with n-BuMgCl but less reactive with bulkier tert-BuMgCl. Adduct dianions can be monoalkylated with alkyl iodides and used in Peterson olefination reactions.