Diethyl bromodifluoromethylphosphonate: a highly efficient and environmentally benign difluorocarbene precursor
作者:Yossi Zafrani、Gali Sod-Moriah、Yoffi Segall
DOI:10.1016/j.tet.2009.04.082
日期:2009.7
thiophenols, using diethyl bromodifluoromethylphosphonate (1) as a difluorocarbene precursor, is described. This commercially available phosphonate was found to undergo an extremely facile P–C bond cleavage on basichydrolysis (−78 °C to rt), presumably leading to the bromodifluoromethyl anion, which subsequently converts to a difluorocarbene intermediate. The latter is trapped by phenolates 2 or thiophenolates
compounds containing the difluoromethyl group, as it is considered a lipophilic hydrogenbonddonor that may act as a bioisostere of hydroxyl, thiol, or amine groups. A series of difluoromethyl anisoles and thioanisoles was prepared and their druglike properties, hydrogenbonding, and lipophilicity were studied. The hydrogenbond acidity parameters A (0.085–0.126) were determined using Abraham’s solute 1H
人们对含二氟甲基的有机化合物越来越感兴趣,因为它被认为是亲脂性的氢键供体,可以作为羟基,巯基或胺基的生物等排体。制备了一系列的二氟甲基茴香醚和硫代苯甲醚,并研究了它们的类药物性质,氢键和亲脂性。氢键酸度参数A(0.085–0.126)使用亚伯拉罕的溶质1 H NMR分析确定。发现二氟甲基基团以与硫酚,苯胺和胺基团相似的规模充当氢键供体,但不如羟基基团那样。尽管二氟被认为是亲油性增强组,实验Δlog的范围 P(水-辛醇)值日志( P(XCF 2 H)– log P(XCH 3))范围从-0.1到+0.4。对于这两个参数,在测量值和Hammettσ常数之间发现线性相关。这些结果可能有助于合理设计含有二氟甲基部分的药物。
S-, N-, and Se-Difluoromethylation Using Sodium Chlorodifluoroacetate
作者:Vaibhav P. Mehta、Michael F. Greaney
DOI:10.1021/ol402370f
日期:2013.10.4
thiols is reported using chlorodifluoroacetate as the difluoromethylating agent. This cheap reagent undergoes smooth decarboxylation at 95 °C to afforddifluorocarbene, which can be trapped with a variety of aromatic and heteroaromatic thiols. The reaction is also effective for the difluoromethylation of heterocyclic nitrogen compounds and phenylselenol.
Visible-Light Photoredox Difluoromethylation of Phenols and Thiophenols with Commercially Available Difluorobromoacetic Acid
作者:Jinyan Yang、Min Jiang、Yunhe Jin、Haijun Yang、Hua Fu
DOI:10.1021/acs.orglett.7b01118
日期:2017.5.19
A simple and efficient visible-light photoredox one-pot method for difluoromethylation of phenols and thiophenols has been developed. The protocol uses commerciallyavailable, inexpensive, and easy handling difluorobromoacetic acid as the difluoromethylating agent, and the diverse O- and S-difluoromethylated products were prepared in good yields with tolerance of many functional groups.
Copper-Promoted Sandmeyer Difluoromethylthiolation of Aryl and Heteroaryl Diazonium Salts
作者:Jiang Wu、Yang Gu、Xuebing Leng、Qilong Shen
DOI:10.1002/anie.201502113
日期:2015.6.22
An efficient copper‐promoted difluoromethylthiolation of aryl and heteroaryldiazoniumsalts is described. The reaction is conducted under mild reaction conditions and various functional groups were compatible. In addition, reactions of heteroaryldiazoniumsalts such as pyridyl, quinolinyl, benzothiazolyl, thiophenyl, carbazolyl, and pyrazolyl diazoniumsalts occurred smoothly to afford the medicinally