作者:Tjark H. Meyer、Ramesh C. Samanta、Antonio Del Vecchio、Lutz Ackermann
DOI:10.1039/d0sc05924b
日期:——
Manganaelectro-catalyzed azidation of otherwise inert C(sp3)–H bonds was accomplished using most user-friendly sodium azide as the nitrogen-source. The operationally simple, resource-economic C–H azidation strategy was characterized by mild reaction conditions, no directing group, traceless electrons as the sole redox-reagent, Earth-abundant manganese as the catalyst, high functional-group compatibility
使用大多数用户友好的叠氮化钠作为氮源,完成了锰电催化的惰性 C(sp 3 )–H 键的叠氮化。操作简单、资源经济的C-H叠氮化策略具有反应条件温和、无导向基团、无痕电子作为唯一氧化还原试剂、地球丰富的锰作为催化剂、高官能团相容性和高化学选择性等特点。生物活性化合物的后期叠氮化阶段。通过实验、分光光度法和循环伏安法进行的详细机理研究为金属催化脂肪族自由基的形成以及随后在锰( III / IV )流形内的叠氮基自由基转移提供了强有力的支持。
Rhodium-catalysed aryloxycarbonylation of iodo-aromatics by 4-substituted phenols with carbon monoxide or paraformaldehyde
作者:Anas Abu Seni、László Kollár、László T. Mika、Péter Pongrácz
DOI:10.1016/j.mcat.2018.07.021
日期:2018.10
for carbonylation reactions. Both strategies proved to be efficient for the synthesis of the corresponding phenyl esters. High pressure reactions provided the ester products with good selectivity, however lower activity was achieved compared to palladium containing systems. Using paraformaldehyde as carbon-monoxide source special reaction conditions are required, thus dramatic changes observed during
Palladium-catalyzed aryloxy- and alkoxycarbonylation of aromatic iodides in γ-valerolactone as bio-based solvent
作者:József M. Tukacs、Bálint Marton、Eszter Albert、Imre Tóth、László T. Mika
DOI:10.1016/j.jorganchem.2020.121407
日期:2020.9
gather some information on the mechanism of these reactions, the effects of electronic parameters (σ) of various aromatic substituents of the aryl iodides as well as the influence of para-substitution of phenol were investigated on the activity. For a comparison, the aryl-substituted aryl iodides were also reacted with methanol and aryl iodide was also alkoxycarbonylated using several different lower
基于化石的溶剂和三乙胺作为有毒和挥发性碱被成功地替换为γ -戊内酯作为非挥发性溶剂和K 2 CO 3使用无膦的Pd催化剂体系在芳基碘化物的烷氧基羰基化和芳氧基羰基化中用作无机碱。这样,传统的系统不仅被简单地替换,而且得到了显着改善。在研究中,详细评估了羰基化效率对不同反应参数(即使用其他几种溶剂,温度,一氧化碳压力,碱和催化剂浓度)的影响。为了收集有关这些反应机理的一些信息,研究了芳基碘化物的各种芳族取代基的电子参数(σ)的影响以及苯酚的对位取代对活性的影响。为了比较,芳基取代的芳基碘化物也与甲醇反应,芳基碘化物也用几种不同的低级醇烷氧基羰基化。从所观察到的芳族取代基的电子参数与速率之间的相关性来看,速率确定步骤似乎是将Ar–I氧化添加到Pd中0,前提是存在足够量的亲核试剂以形成酯。如果不是这种情况,亲核试剂的攻击速率可能决定总体速率。
Visible-Light-Promoted Site-Specific and Diverse Functionalization of a C(sp<sup>3</sup>)–C(sp<sup>3</sup>) Bond Adjacent to an Arene
作者:Yaxin Wang、Nengyong Wang、Jianyou Zhao、Minzhi Sun、Huichao You、Fang Fang、Zhong-Quan Liu
DOI:10.1021/acscatal.0c01495
日期:2020.6.19
We report here a strategy for inert C–C bondfunctionalization. Site-specific cleavage and functionalization of a saturated C(sp3)–C(sp3) bond via a visible-light-induced radical process have been achieved. The general features of this reaction are as follows. (1) Both linear and cyclic C(sp3)–C(sp3) bonds with a vicinal arene can be specifically functionalized. (2) One carbon is converted into a ketone
[EN] REAGENTS AND METHODS FOR GLYCOSYLATION<br/>[FR] RÉACTIFS ET MÉTHODES DE GLYCOSYLATION
申请人:UNIV FLORIDA
公开号:WO2018035416A1
公开(公告)日:2018-02-22
The invention provides methods and regents for the glycosylation of organic molecules. In one aspect, the invention provides a method for glycosylating a hydroxyl-containing organic compound (i.e., a glycosyl acceptor) comprising contacting a glycosyl donor with the hydroxyl-containing organic compound, in the presence of an oxidant, to yield a glycosylated organic compound. In certain embodiments, the methods provided herein provide glycosylation products with high anomeric selectivity. The methods can be applied to the synthesis of disaccharides, trisaccharides, polysaccharides, glycans, etc. Also provided herein are compounds (e.g., glycosyl donors and acceptors) which are useful building blocks in the provided reactions.