Use of Trifluoromethyl Groups for Catalytic Benzylation and Alkylation with Subsequent Hydrodefluorination
作者:Jiangtao Zhu、Manuel Pérez、Christopher B. Caputo、Douglas W. Stephan
DOI:10.1002/anie.201510494
日期:2016.1.22
The electrophilic organofluorophosphonium catalyst [(C6F5)3PF][B(C6F5)4] is shown to effect benzylation or alkylation by aryl and alkyl CF3 groups with subsequenthydrodefluorination, thus resulting in a net transformation of CF3 into CH2–aryl fragments. In the case of alkyl CF3 groups, Friedel–Crafts alkylation by the difluorocarbocation proceeded without cation rearrangement, in contrast to the corresponding
亲电子性有机氟phosph催化剂[(C 6 F 5)3 PF] [B(C 6 F 5)4 ]显示出通过芳基和烷基CF 3基团进行苄基化或烷基化,随后进行加氢脱氟,从而导致CF的净转化3成CH 2-芳基片段。在烷基CF 3基团的情况下,与烷基单氟化物的相应反应相反,通过二氟碳羰基化进行的Friedel-Crafts烷基化反应没有阳离子重排。
9-Borabicyclo[3.3.l]nonane-induced Friedel–Crafts benzylation of arenes with benzyl fluorides
作者:Jing Guo、Karlee L. Bamford、Douglas W. Stephan
DOI:10.1039/c9ob00912d
日期:——
Friedel-Craftsbenzylation of arenes with benzyl fluorides using 9-borabicyclo[3.3.l]nonane (9-BBN) as a mediator has been developed. This provides a simple and cheap route to the activation of C-F bonds to synthesize 1,1-diarylmethanes in good to excellent yields (up to 98%) under mild conditions. Functional group tolerance and the mechanism are considered.
Highly efficient Friedel–Crafts-type benzylation via benzyl cations generated in multiple spacer-molecule separated ion-pairs
作者:Ron W. Darbeau、Gregory A. Trahan、Luis M. Siso
DOI:10.1039/b312664a
日期:——
Deamination, as a facile route to highly reactivecarbocations, is of interest to several areas of organic chemistry, industry, and medicine. The reactivity and utility of these carbocations derives from the presence of a lone nitrogenous entity (N(2) or N(2)O) interposed between the ion-pair. We report here the synthesis of a new deamination precursor whose nitrosation and subsequent decomposition
The conformational distribution in diphenylmethane determined by nuclear magnetic resonance spectroscopy of a sample dissolved in a nematic liquid crystalline solvent
作者:G. Celebre、G. De Luca、J. W. Emsley、E. K. Foord、M. Longeri、F. Lucchesini、G. Pileio
DOI:10.1063/1.1555631
日期:2003.4.8
The deuterium decoupled, proton nuclear magneticresonance spectrum of a sample of diphenylmethane-d3 dissolved in a nematic liquidcrystallinesolvent has been analyzed to yield a set of dipolar couplings, Dij. These have been used to test models for the conformational distribution generated by rotation about the two ring-CH2 bonds through angles τ1 and τ2. Conformational distributions, particularly
Wet and Dry Processes for the Selective Transformation of Phosphonates to Phosphonic Acids Catalyzed by Brønsted Acids
作者:Chunya Li、Yuta Saga、Shun-ya Onozawa、Shu Kobayashi、Kazuhiko Sato、Norihisa Fukaya、Li-Biao Han
DOI:10.1021/acs.joc.0c00550
日期:2020.11.20
substituents of the phosphonateesters, the conversion to the corresponding phosphonic acids can be achieved under milder conditions in the absence of water (the dry process). Thus, the conversion of dibenzyl phosphonates to the corresponding phosphonic acids took place smoothly at 80 °C in toluene or benzene in high yields. Moreover, selective conversion of benzyl phosphonates RP(O)(OR′)(OBn) to the