A truly catalytic nucleophilic trifluoromethylation reaction of carbonyl compounds with Ruppert’s reagent, Me3SiCF3, has been shown to be efficiently promoted by a P(t-Bu)3-DMF system. Imines were also converted to the desired α-trifluoromethyl amines under similar reaction conditions.
A New and Efficient Method for the Trifluoromethylation of Carbonyl Compounds with Trifluoromethyltrimethylsilane in DMSO
作者:Takeshi Oriyama、Katsuyuki Iwanami
DOI:10.1055/s-2005-922767
日期:——
In the presence of MS 4 A in DMSO, trifluoromethylation of various aldehydes and ketones with trifluoromethyltrimethylsilane (TMSCF 3 ) proceeded very smoothly to give the corresponding trifluoromethylated adduct in goodto quantitative yields without a base catalyst.
在 DMSO 中存在 MS 4 A 的情况下,各种醛和酮与三氟甲基三甲基硅烷 (TMSCF 3 ) 的三氟甲基化非常顺利地进行,以良好的定量产率得到相应的三氟甲基化加合物,无需碱催化剂。
A Hammett Study of Clostridium acetobutylicum Alcohol Dehydrogenase (CaADH): An Enzyme with Remarkable Substrate Promiscuity and Utility for Organic Synthesis
作者:Gaurav P. Kudalkar、Virendra K. Tiwari、Joshua D. Lee、David B. Berkowitz
DOI:10.1055/s-0039-1691576
日期:2020.2
free-energy relationship (LFER) study across three distinct classes of carbonyl substrates; namely aryl aldehydes, aryl β-keto esters and aryl trifluoromethyl ketones. Rates are measured by monitoring the decrease in NADPH fluorescence at 460 nm with time across a range of substrate concentrations for each member of each carbonylcompound class. The resulting v 0 versus [S] data are subjected to least-squares
The first Lewis acid-catalyzed trifluoromethylation reactions of aldehydes with Me3SiCF3 under TiF4/DMF, Ti(OiPr)4/DMF and Cu(OAc)2/dppp/toluene conditions are described. We have successfully applied this methodology to the difluoromethylation of aldehydes using Me3SiCF2SePh, Me3SiCF2P(O)OEt2 and Me3SiCF2SPh.
Ammonium bromides/KF catalyzed trifluoromethylation of carbonyl compounds with (trifluoromethyl)trimethylsilane and its application in the enantioselective trifluoromethylation reaction
has been performed by treatment of Me3SiCF3 under initiation by TBAF, TBAT, TMAF as well as CsF. However, these commercially available fluorides are rather expensive and moisture sensitive. Potassiumfluoride (KF) is an inexpensive and commonly used fluoridesource and can be also used as an initiator for the trifluoromethylation, but the method suffers from the significant limitation that only DMF