Enantiomerically pure triflones R1CH(R2)SO2CF3 have been synthesized starting from the corresponding chiral alcohols via thiols and trifluoromethylsulfanes. Key steps of the syntheses of the sulfanes are the photochemical trifluoromethylation of the thiols with CF3Hal (Hal=halide) or substitution of alkoxyphosphinediamines with CF3SSCF3. The deprotonation of RCH(Me)SO2CF3 (R=CH2Ph, iHex) with nBuLi
The pK(a) values of a series of fluoroalkanesulfonylamides were measured by potentiometric titration. Different kinds of alkyl halides and tosylates were employed to investigate the nucleophilicity of fluoroalkanesulfonylamides. Fluoroalkanesulfonylamides with longer fluoroalkyl chain have weaker nucleophilicity. (C) 2010 Elsevier B.V. All rights reserved,
Triflamides: Elimination of the triflyl anion versus substitution of the trifluoromethide group
Base-induced elimination of CF3SO2- and nucleophilic substitution of CF3- were observed in the reaction of secondary triflamides with alkyllithium reagents.
N-Benzyltriflamide: A generally useful mitsunobu reagent for amine synthesis
作者:Kathryn E. Bell、David W. Knight、Michael B. Gravestock
DOI:10.1016/0040-4039(95)01792-g
日期:1995.11
N-Benzyl triflamide has been found to be generally useful as a Mitsunobunucleophile for the preparation of a range of primary and secondary benzylamines from the corresponding alcohols, using the standard reagents DEAD and triphenylphosphine.
The Gabriel synthesis is generalized as monoalkylation of an ammonia or primary amine derivative with subsequent removal of the derivatizing group(s) from nitrogen. Two new derivatives for this purpose are introduced: phenacylsulfonamides and triflamides, with discussion of their generality and effectiveness.