Linear copolymers of ethylene and acrylonitrile were prepared using palladium complexes bearing phosphine-sulfonate bidentate ligands. Acrylonitrile units located in the linear polyethylene backbones were detected for the first time by 13C NMR spectroscopy. Catalyst systems employing isolated palladium complexes such as 3 showed much higher activity for the copolymerization than the in situ generation
Highly Z-selective synthesis of α,β-unsaturated nitriles using the Horner–Wadsworth–Emmons reaction
作者:Kaori Ando、Miho Okumura、Shigeo Nagaya
DOI:10.1016/j.tetlet.2013.02.020
日期:2013.4
A new HWE reagent, (o-tBuC6H4O)2P(O)CH2CN (2e), reacts with various types of aldehydes to give Z-α,β-unsaturatednitriles with 86% to >99% Z-selectivity. Especially, the reaction of 2e with bulkier aldehydes, both aromatic and aliphatic, gave the Z-olefins with extremely high selectivity. The combination of t-BuOK and 18-crown-6 (1 equiv) is the base of choice for aromatic aldehydes and t-BuOK is generally
一种新的HWE试剂(o - t BuC 6 H 4 O)2 P(O)CH 2 CN(2e)与各种类型的醛反应生成Z -α,β-不饱和腈,含量为86%至> 99%Z选择性。特别地,2e与较大的醛(芳族和脂族)的反应使Z-烯烃具有极高的选择性。的组合吨-BuOK和18-冠-6(1当量)是选择用于芳族醛的基极和吨-BuOK通常是选择用于脂族醛的碱。
Dual [Fe+Phosphine] Catalysis: Application in Catalytic Wittig Olefination
Iron hydride complexes of the general formula P2Fe(NO)CO)H are highly active catalysts for the hydrosilylation of aldehydes or ketones and phosphine oxides. Depending on the solvent, the in situ reduction of the phosphine oxide can be faster than the corresponding hydrosilylation of a carbonyl group. This unusual activity was used within the context of catalytic Wittig olefination.
Copper-catalyzed direct transformation of simple alkynes to alkenyl nitriles via aerobic oxidative N-incorporation
作者:Xiaoqiang Huang、Xinyao Li、Ning Jiao
DOI:10.1039/c5sc02126j
日期:——
A novel direct transformation of aliphatic terminal alkynes to alkenyl nitriles through the incorporation of a nitrogen atom into the simple hydrocarbons has been reported. The usage of inexpensive copper catalyst, O2 as the sole oxidant, broad substrate scope as well as feasibility for “late-stage modification” make this protocol very promising. Mechanistic studies including DFT calculation demonstrate
Thiourea-Mediated Stereospecific Deoxygenation of Cyanoepoxides to Access Highly Diastereopure Alkenyl Nitriles
作者:Yujie Zhang、Shukui Shi、Zhanhui Yang
DOI:10.1021/acs.joc.3c02869
日期:2024.2.16
A practical and efficient protocol for synthesis of >99% diastereopure Z- and E-alkenyl nitriles is developed, through tetramethylthiourea-mediated stereospecificdeoxygenation of respective cis- and trans-cyanoepoxides in ethanol. The desired products are obtained in excellent yields.