SN2 Substitution Reactions at the Amide Nitrogen in the Anomeric Mutagens, N-Acyloxy-N-alkoxyamides
作者:Katie L. Cavanagh、Stephen A. Glover、Helen L. Price、Rhiannon R. Schumacher
DOI:10.1071/ch09166
日期:——
amide character and resemble α-haloketones in reactivity. They are susceptible to SN2reactions at nitrogen, a process that is responsible for their mutagenic behaviour. Kinetic studies have been carried out with the nucleophile N-methylaniline that show that, like SN2reactions at carbon centres, the rate constant for SN2 displacement of carboxylate is lowered by branching β to the nitrogen centre, or
N-酰氧基-N-烷氧基酰胺1a是不寻常的异头异构酰胺,其由于双氧基取代而在氮上呈锥体状。通过这种构型,它们失去了大部分酰胺特性,并且在反应性上类似于α-卤代酮。它们在氮气下易受S N 2反应的影响,这是导致其诱变行为的原因。动力学研究已经进行了与亲核试剂Ñ甲基苯胺,显示的是,最喜欢S ñ在碳中心,速率常数为S 2个的反应Ñ通过将β分支到氮中心或烷氧基侧链上的大体积基团,可降低2羧酸盐的置换。然而,羧酸酯离去基团上的支链或大体积基团不影响取代率,其主要由离去的羧酸酯基团的p K A控制。这些结果与氨与N-乙酰氧基-N-甲氧基乙酰胺的模型反应的计算性质相符,但与空间效应对其致突变性的作用相反。
Reusable ionic liquid-catalyzed oxidative esterification of carboxylic acids with benzylic hydrocarbons via benzylic Csp<sup>3</sup>–H bond activation under metal-free conditions
作者:Fen Mou、Yadong Sun、Weiwei Jin、Yonghong Zhang、Bin Wang、Zhiqing Liu、Lei Guo、Jianbin Huang、Chenjiang Liu
DOI:10.1039/c7ra02788e
日期:——
A metal-free protocol for the direct oxidativeesterification of the Csp3–H bond in benzylic hydrocarbons with carboxylic acids using heterocyclic ionic liquid as catalyst has been reported. The catalyst 1-butylpyridinium iodide could be easily recycled and reused for at least four cycles without obvious loss of catalytic activity.
Esterification of the Primary Benzylic C–H Bonds with Carboxylic Acids Catalyzed by Ionic Iron(III) Complexes Containing an Imidazolinium Cation
作者:Bing Lu、Fan Zhu、Hong-Mei Sun、Qi Shen
DOI:10.1021/acs.orglett.7b00148
日期:2017.3.3
The first iron-catalyzedesterification of the primary benzylic C–H bonds with carboxylic acids using di-tert-butyl peroxide as an oxidant is achieved by novel ionic iron(III) complexes containing an imidazolinium cation. The use of well-defined, air-stable, and available iron(III) complex in a 5 mol % loading and readily available starting materials with a broad generality and outstanding sterically
An efficient metal‐free oxidative esterification of benzylCHbonds was developed. Using tetrabutylammonium iodide as catalyst and tert‐butyl hydroperoxide as co‐oxidant, benzylic substrates could react smoothly with various carboxylic acids to give the esters with good to excellent yields. The method was also suitable for the O‐protection of N‐Boc amino acids. The reaction mechanism was primarily
Copper Catalyzed Oxidative Esterification of Aldehydes with Alkylbenzenes via Cross Dehydrogenative Coupling
作者:Saroj Kumar Rout、Srimanta Guin、Krishna Kanta Ghara、Arghya Banerjee、Bhisma K. Patel
DOI:10.1021/ol301756y
日期:2012.8.3
Copper(II) as the catalyst in a crossdehydrogenativecoupling (CDC) reaction has been demonstrated for the synthesis of benzylic esters using aldehydes and alkylbenzenes as coupling partners.