Preparation and synthetic utility of fluorinated phosphonium salts, -phosphonium salts and phosphoranium salts [1]
作者:Donald J. Burton
DOI:10.1016/s0022-1139(00)81218-x
日期:1983.10
fluorohalomethanes provides a rapid and high yield synthesis of various types of fluorinated phosphonium salts, bis-phosphonium salts and phosphoranium salts. These salts are useful precursors to fluorine-containing ylides, carbenes and methide ions. Examples of the preparation, mechanism of formation, and syntheticutility of these novel reagents is described.
Monofluoroalkenylation of Dimethylamino Compounds through Radical–Radical Cross‐Coupling
作者:Jin Xie、Jintao Yu、Matthias Rudolph、Frank Rominger、A. Stephen K. Hashmi
DOI:10.1002/anie.201602347
日期:2016.8
An unprecedented and challenging radical–radicalcross‐coupling of α‐aminoalkyl radicals with monofluoroalkenyl radicals derived from gem‐difluoroalkenes was achieved. This first example of tandem C(sp3)−H and C(sp2)−F bond functionalization through visible‐light photoredox catalysis offers a facile and flexible access to privileged tetrasubstituted monofluoroalkenes under very mild reaction conditions
Photocatalytic syntheses of gem-difluoroolefins were performed using the B12–TiO2 hybrid catalyst during the CC bondreduction of α-trifluoromethyl styrenes with C–F bondcleavage at room temperature under nitrogen. The gem-difluoroolefins were used as synthetic precursors for fluorinated cyclopropanes.
The hydrodefluorination of CF3-substituted alkenes can be catalyzed by a nickel(II) hydride bearing a pincer ligand. The cata-lyst loading can be as low as 1 mol%. gem-Difluoroalkenes containing a number of functional groups can be formed in good to excellent yields, by a radical mechanism initiated by H• transfer from the nickel hydride. The relative reactivity of various substrates supports the proposed
CF3 取代烯烃的加氢脱氟可以由带有钳状配体的镍 (II) 氢化物催化。催化剂负载量可以低至 1 mol%。通过从氢化镍中转移 H• 引发的自由基机制,可以以良好到极好的产率形成含有许多官能团的 gem-二氟烯烃。各种底物的相对反应性支持所提出的机制,TEMPO 捕获实验也是如此。
Preparation of 1-Aryl-2-chloro-3,3-difluorocyclopropenes
作者:Chuan-Chen Lee、Shaw-Tao Lin
DOI:10.1055/s-2000-6358
日期:——
A series of stable 1-aryl-2-chloro-3,3-difluorocyclopropenes were prepared from the reaction of 2′,2′-difluorostyrene and chloroform in aq 40% NaOH solution in good yields.