Anion-Initiated Trifluoromethylation by TMSCF<sub>3</sub>: Deconvolution of the Siliconate–Carbanion Dichotomy by Stopped-Flow NMR/IR
作者:Craig P. Johnston、Thomas H. West、Ruth E. Dooley、Marc Reid、Ariana B. Jones、Edward J. King、Andrew G. Leach、Guy C. Lloyd-Jones
DOI:10.1021/jacs.8b06777
日期:2018.9.5
suppliers, also affect the kinetics. Some reactions are complete in milliseconds, others take hours, and others stall before completion. Despite these differences, a general mechanism has been elucidated in which the product alkoxide and CF3– anion act as chain carriers in an anionic chain reaction. Silyl enolether generation competes with 1,2-addition and involves protonation of CF3– by the α-C–H of the
Potassium Alkoxide as an Efficient Catalyst for Nucleophilic Perfluoroalkylation: Attempt at Anion-Controlled Enantioselective Insertion of a Trifluoromethyl Group
Potassiumalkoxide was found to be a highly active catalyst for the nucleophilic trifluoromethylation of carbonyl compounds. The catalytic system was successfully applied to the reactions of both aldehydes and ketones, affording the corresponding trifluoromethylated products in high yields at low catalyst loadings (0.1–0.01 mol%) in several solvents, such as THF, toluene, and CH2Cl2. In addition, the
发现醇钾是羰基化合物的亲核三氟甲基化的高活性催化剂。该催化体系成功地应用于醛和酮的反应,在 THF、甲苯和 CH 2 Cl 2等几种溶剂中以低催化剂负载量(0.1-0.01 mol%)以高产率提供相应的三氟甲基化产物。此外,含有 ( S )-2,2'-双[双(3,5-二甲基苯基)膦基]-1,1'-联萘 [( S )-XylBINAP]的 Ru(II) 络合物的钾盐配体和两个l原位制备的-苏糖酸盐配体催化芳族醛的对映选择性三氟甲基化,尽管 ee 值不令人满意(小于 20%)。
Synthesis of α-(Trifluoromethyl)styrenes and 1,3-Di(trifluoromethyl)indanes via Electrophilic Activation of TMS Ethers of (Trifluoromethyl)benzyl Alcohols in Brønsted Acids
作者:Olesya V. Khoroshilova、Irina A. Boyarskaya、Aleksander V. Vasilyev
DOI:10.1021/acs.joc.2c01961
日期:2022.12.2
CF3-benzyl alcohols (and their heterocyclic analogues) undergo elimination of TMSOH molecule with the formation of α-(trifluoromethyl)styrenes in yields of up to 90% under the action of strong Brønsted acids TfOH or H2SO4. Under the acidic conditions upon prolongation of the reaction, the α-(trifluoromethyl)styrenes are further dimerized into cis-/trans-1,3-di(trifluoromethyl)indanes in yields of up to