已开发出一种快速有效的方案,用于从烷基卤化物和伯胺或仲胺合成 N,N'-二取代脲衍生物。合成途径结合了亲核取代和 Staudinger-aza-Wittig 反应,在聚合物结合的二苯基膦存在下,在 14 bar 的 CO2 压力下,并在一个一锅两步法中进行。该协议在微波辐射下进行了优化,放大实验是在帕尔反应器的常规条件下进行的。最终化合物在简单过滤后以几乎定量的总产率分离,这使得该过程容易且快速执行。
Chemoselective isocyanide insertion into the N–H bond using iodine–DMSO: metal-free access to substituted ureas
作者:Porag Bora、Ghanashyam Bez
DOI:10.1039/c8cc05019h
日期:——
Insertion of isocyanides into the N–H bond gives access to many medicinally important and structurally diverse complex nitrogen-containing heterocycles. Although the transition metal catalyzed isocyanideinsertion into the N–H bond is very common, polymerization of isocyanides in the presence of a transition metal and their strong coordination with metals are the common drawbacks. On the other hand
A solvent in which dichloromethane is mixed with alcohol as a poor solvent is used for preparing a dope. Alcohol is supplied to the dope in a inline pipe to mix with a static mixer, such as a casting dope in which a composition of alcohol is increased. The temperature of the rotary drum is adjusted to −7° C. The casting dope is fed from a casting die to the rotary drum so as to form a casting film whose thickness is 40 μm. Since the content of alcohol is high and a storage modulus of the cooled casting film is at least 150 thousands Pa, the peeling defect does not occur, and the stretch is reduced as far as possible. A gel-like film is dried by a tenter type drying device, and stretched such that the stretch ratio is at most 110%. The produced film is thin and excellent in a surface condition and optical isotropy.
A fast and efficient protocol for the synthesis of N,N'-disubstituted urea derivatives from alkyl halides and primary or secondary amines has been developed. The synthetic pathway combines nucleophilic substitutions and a Staudinger-aza-Wittig reaction in the presence of polymer-bound diphenylphosphine under 14 bar of CO2 pressure and has been performed in a one-pot two-step process. The protocol has
已开发出一种快速有效的方案,用于从烷基卤化物和伯胺或仲胺合成 N,N'-二取代脲衍生物。合成途径结合了亲核取代和 Staudinger-aza-Wittig 反应,在聚合物结合的二苯基膦存在下,在 14 bar 的 CO2 压力下,并在一个一锅两步法中进行。该协议在微波辐射下进行了优化,放大实验是在帕尔反应器的常规条件下进行的。最终化合物在简单过滤后以几乎定量的总产率分离,这使得该过程容易且快速执行。
Carbon-Bonding Metal Catalysis (CBMC): A Supramolecular Complex Directs Structural-Isomer Selection in Gold-Catalyzed Reactions
作者:Xinxin Li、Lingfei Hu、Gang Lu、Yao Wang
DOI:10.1021/jacs.3c07551
日期:2023.10.4
bonding and metal catalysis together and demonstrated that a supramolecular carbon-bonding metal complex can not only give rise to catalytic activity but, more remarkably, direct structural-isomer selection events in gold-catalyzed reactions. The experimental results unveil the fact that the imposing of weak carbon-bonding interactions on a gold complex can alter the carbene as well as the Lewis acid