描述了在碱性条件下使用(溴二氟甲基)膦酸二乙酯 ( 1 )对各种基于S - 和O - 的亲核试剂进行有效二氟甲基化,呈现出广泛的 p K a值。这些反应依赖于通过1水解形成的二氟卡宾的定量产生,发现只有当起始材料的 p K a值小于约1时才有效。11. 重要的是,在底物具有两个或三个亲核中心的情况下,该特征成功实现以实现中心的高化学或区域选择性二氟甲基化,表现出最低的 p K一个值和最高极化。
Deoxygenative <i>gem</i>-difluoroolefination of carbonyl compounds with (chlorodifluoromethyl)trimethylsilane and triphenylphosphine
作者:Fei Wang、Lingchun Li、Chuanfa Ni、Jinbo Hu
DOI:10.3762/bjoc.10.32
日期:——
phosphonium ylide represents one of the most straightforward methods. RESULTS: The combination of (chlorodifluoromethyl)trimethylsilane (TMSCF2Cl) and triphenylphosphine (PPh3) can be used for the synthesis of gem-difluoroolefins from carbonyl compounds. Comparative experiments demonstrate that TMSCF2Cl is superior to (bromodifluoromethyl)trimethylsilane (TMSCF2Br) and (trifluoromethyl)trimethylsilane
Difluoroiodomethane: practical synthesis and reaction with alkenes
作者:Pin Cao、Jian-Xing Duan、Qing-Yun Chen
DOI:10.1039/c39940000737
日期:——
Difluorocarbene precusors 2, FSO2CF2COF, FSO2CF2CO2H, FSO2CF2CO2Me and XCF2CO2M react with Kl to give HCF2l 1 in high yields; a smooth reaction of 1 with alkenes or alkynes in the presence of Na2S2O4 gives the difluoromethylated adducts in good yields.
Synthesis of<i>gem</i>-Difluorocyclopropa(e)nes and O<i>-</i>, S<i>-</i>, N<i>-</i>, and P-Difluoromethylated Compounds with TMSCF<sub>2</sub>Br
作者:Lingchun Li、Fei Wang、Chuanfa Ni、Jinbo Hu
DOI:10.1002/anie.201306703
日期:2013.11.18
Two-in-one: Me3 SiCF2 Br is an efficient difluorocarbene source and is compatible with both neutral and aqueous basic conditions. Bromide-ion-initiated [2+1] cycloaddition with alkenes/alkynes and hydroxide ion promoted α-addition with (thio)phenols, (thio)alcohols, sulfinates, heterocyclic amines, and H-phosphine oxides give the corresponding gem-difluorinated compounds with broad functional-group tolerance.
Soborowskii; Baina, Zhurnal Obshchei Khimii, 1959, vol. 29, p. 1142; engl.Ausg. S.1113
作者:Soborowskii、Baina
DOI:——
日期:——
Regio- and chemoselectivity in S- and O- difluoromethylation reactions using diethyl (bromodifluoromethyl)phosphonate
The effective difluoromethylations of various S- and O- based- nucleophiles, presenting a wide range of pKa values, using diethyl(bromodifluoromethyl) phosphonate (1) under basic conditions is described. These reactions, which rely on the quantitative generation of difluorocarbene formed through the hydrolysis of 1, were found to be effective only once the starting materials had pKa values of less
描述了在碱性条件下使用(溴二氟甲基)膦酸二乙酯 ( 1 )对各种基于S - 和O - 的亲核试剂进行有效二氟甲基化,呈现出广泛的 p K a值。这些反应依赖于通过1水解形成的二氟卡宾的定量产生,发现只有当起始材料的 p K a值小于约1时才有效。11. 重要的是,在底物具有两个或三个亲核中心的情况下,该特征成功实现以实现中心的高化学或区域选择性二氟甲基化,表现出最低的 p K一个值和最高极化。