Novel applications of 2-cyanoethylanilines in the synthesis of conjugated primary and secondary anilines

2-Cyanoethyl anilines were controllably cleaved by 1 equiv of potassium t-butoxide in dry THF with a reaction that can be used in situ with the Wittig reaction to synthesize conjugated primary and secondary anilines.     

t—BuNO二聚体在不同溶剂中裂解机理的研究

本文利用＾１ＨＮＭＲ，ＵＶ－Ｖｉｓ方法，研究了ｔ－ＢｕＮＯ二聚体在有机溶剂及水溶液中的裂解反应产物，分析了其反应的动力学，提出了在非极性的有机相中ｔ－ＢｕＮＯ二聚体为均裂反应，而在极性的水相中为均裂和异裂同时进行的竞争反应。     

Smart cleavage reactions: the synthesis of benzimidazoles and benzothiazoles from polymer-bound esters

The preparation of an array of benzimidazoles and benzothiazoles from polymer-bound esters is described. Polymer-bound esters were treated with 2-aminothiophenols or 1,2-phenylenediamines in the presence of a Lewis acid to afford the corresponding benzothiazole or benzimidazole cleavage products. The reaction of 2-aminophenols with the polymer-bound esters failed to give the desired benzoxazole products using this procedure.     

Synthesis of thio- and selenoglycosides by cleavage of dichalconides in the presence of zinc/zinc chloride and reaction with glycosyl bromides

A convenient odorless methodology has been devised for the preparation of 1,2-trans-thio- and selenoglycosides through zinc-mediated cleavage of disulfides and diselenides and reaction of the thiolate and selenides formed in situ with glycosyl bromides. The yields were excellent in all cases.     

Synthesis of 13-acylamino-huprines: different behavior of diastereomeric 13-methanesulfonamido-huprines on PPA-mediated hydrolysis

Two diastereomeric pairs of rationally designed huprines additionally substituted at position 13 with a formamido or an acetamido group have been synthesized as potential high affinity acetylcholinesterase inhibitors. The synthetic sequence involves hydrolysis of two diastereomeric 13-methanesulfonamido-huprines, followed by acylation of the resulting diastereomeric amines. In the hydrolysis reaction, carried out with PPA under harsh conditions, significant amounts of cyclized or rearranged by-products were also formed, depending on the stereochemistry of the starting compound.     

Preparation of Aryl‐Substituted E‐Homoallylic Bromides from Cyclopropylcarbinol and PBr3

An expeditious synthesis of aryl substituted E‐homoallylic bromides has been accomplished by the cleavage of cyclopropylcarbinols with phosphorus tribromide.     

Oxidative Deoximation with Sodium Perborate1

An efficient and convenient conversion of oximes to corresponding carbonyl compounds with sodium perborate in glacial acetic acid is reported.     

Odorless Preparation of Thioglycosides and Thio‐Michael Adducts of Carbohydrate Derivatives

A general, odorless, one‐pot methodology has been developed for the preparation of 1,2‐trans‐thioglycosides and thio‐Michael addition products of carbohydrate derivatives through triphenyl phosphine‐mediated cleavage of disulfides and reaction of the thiolate formed in situ with glycosyl bromides and glycosyl conjugated alkenes.     

手性钌(Ⅱ)配合物对DNA的立体选择性断裂

八面体钌(Ⅱ)多吡啶配合物与双螺旋DNA插入结合后具有较强的结合能力,并且含有一个具有氧化一还原活性的中心金属离子．它们对氧化剂相对比较稳定,但对光比较敏感,因此可利用光辐射使之产生单线态氧或羟基自由基等而使DNA裂解．此外,这些配合物具有左手∧-和右手△-两种构型,与同样具有手性的DNA作用时,存在着立体选择性结合．并且在对DNA的断裂反应中也存在一定的立体选择性,可作为不同构型DNA的结构探针．     

Cleavage of Menger’s aliphatic amide: A model for peptidase enzyme solely explained by proximity orientation in intramolecular proton transfer

Ab initio HF/6-31G and DFT B3LYP/6-31G (d,p) calculations for the cleavage of Menger’s aliphatic amide 3 (a peptidase model) under physiological conditions, indicate that the rate limiting step in the cleavage process is a proton transfer from one of the carboxyl groups onto the amidic carbonyl oxygen. The acceleration in rates is mainly due to proximity orientation, and the effect of pseudoallylic strain relief on the rates is negligible. Moreover, the calculations reveal that the mode and the mechanism of the amide cleavage are largely dependent on the pH of the reaction. These results explain the findings that peptidase enzymes are reactive around neutral pH while their activities vanish under basic medium.