Difluoromethylation of the activated X–H bond and aliphatic thiols, and gem-difluorocyclopropenation of alkynes with difluorocarbene generated by decarboxylation are described.
Synthesis of gem-Difluorinated Cyclopropanes and Cyclopropenes: Trifluoromethyltrimethylsilane as a Difluorocarbene Source
作者:Fei Wang、Tao Luo、Jinbo Hu、Ying Wang、Hema S. Krishnan、Parag V. Jog、Somesh K. Ganesh、G. K. Surya Prakash、George A. Olah
DOI:10.1002/anie.201101691
日期:2011.7.25
Highly versatile: The Ruppert–Prakash reagent (Me3SiCF3) can be an efficient source of difluorocarbene. By varying the nonmetallic initiator that is used (F− at lower temperatures and I− at higher temperatures), a range of structurally diverse alkenes and alkynes can be converted into the corresponding gem‐difluorinated cyclopropanes and cyclopropenes in good yields (see scheme).
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.