An efficient route to 3-trifluoromethylpyrazole via cyclization/1,5-H shift and its applications in the synthesis of bioactive compounds
摘要:
A methodology for regioselective synthesis of 3-trifluoromethylpyrazole from the reaction of trifluoromethyl alkenone and tosylhydrazone has been developed. The reaction was proposed to proceed through a tandem cyclization and 1,5-H shift reaction, which can be applied to the synthesis of bioactive compounds like Celecoxib, Mavacoxib, and SC-560. (C) 2015 Elsevier Ltd. All rights reserved.
Oxidation of α-Trifluoromethyl Alcohols Using a Recyclable Oxoammonium Salt
作者:Christopher B. Kelly、Michael A. Mercadante、Trevor A. Hamlin、Madison H. Fletcher、Nicholas E. Leadbeater
DOI:10.1021/jo301477s
日期:2012.9.21
method for the oxidation of α-trifluoromethyl alcohols to trifluoromethyl ketones (TFMKs) using the oxoammonium salt 4-acetylamino-2,2,6,6-tetramethylpiperidine-1-oxoammonium tetrafluoroborate (1) is described. Under basic conditions, oxidation proceeds rapidly and affords good to excellent yields of TFMKs, without concomitant formation of the hydrate. The byproduct of the oxidation, 4-acetylamino-2
Synthesis of Fluoroalkylated β-Aminophosphonates and Pyridines from Primary β-Enaminophosphonates
作者:Francisco Palacios、Ana M. Ochoa de Retana、Julen Oyarzabal、Sergio Pascual、Guillermo Fernández de Trocóniz
DOI:10.1021/jo8005667
日期:2008.6.1
and efficient stereoselective synthesis of fluorine containing β-aminophosphonates by reduction of β-enaminophosphonates is described. Reduction with sodium cyanborohydride in the presence of zinc chloride and the catalytic hydrogenation of β-enaminophosphonates gives β-aminophosphonates. β-Enaminophosphonates are also used as intermediates for the regioselective synthesis of fluoroalkyl-substituted pyridines
One-pot Preparation of 2,6-Disubstituted 4-(Trifluoromethyl)pyrimidines <i>via</i> the Tandem Cyclization, Dehydration, and Oxidation Reaction of α,β-Unsaturated Trifluoromethyl Ketones Using POCl<sub>3</sub>-Pyridine-Silica Gel and MnO<sub>2</sub> Systems
The treatment of α,β-unsaturated trifluoromethyl ketones with amidines in acetonitrile gave the corresponding 4-hydroxy-4-(trifluoromethyl)-3,5,6-trihydropyrimidines, followed by successive dehydration with phosphorus oxychloride-pyridine-silica gel and oxidation with manganese(IV) oxide, producing 2,6-disubstituted 4-(trifluoromethyl)pyrimidines in good to excellent yields.
Preparation of Fluoroalkyl Imines, Amines, Enamines, Ketones, α-Amino Carbonyls, and α-Amino Acids from Primary Enamine Phosphonates
作者:Francisco Palacios、Ana María Ochoa de Retana、Sergio Pascual、Julen Oyarzabal
DOI:10.1021/jo048682m
日期:2004.12.1
A simple method for preparation of fluoroalkyl β-enaminophosphonates 1 from alkylphosphonates 2 and perfluoroalkyl nitriles 3 is reported. Olefination reaction of functionalized phosphates 1 with aldehydes gives α,β-unsaturated imines 5. Acid hydrolysis of these fluoroalkyl derivatives 5 affords α,β-unsaturated ketones 6, while their selectivereduction with hydrides leads to the formation of allylamines
A Weinreb amide approach to the synthesis of trifluoromethylketones
作者:DiAndra M. Rudzinski、Christopher B. Kelly、Nicholas E. Leadbeater
DOI:10.1039/c2cc35037h
日期:——
A novel route to access trifluoromethylketones (TFMKs) from Weinreb amides is reported. This represents the first documented case of the Ruppert–Prakash reagent (TMS–CF3) reacting in a constructive manner with an amide and enables synthesis of TMFKs without risk of over-trifluoromethylation.