EWG assisted nucleophilic fluorination using PPHF: a strategy for the synthesis of 1,2,2-triaryl-2-fluoroethanones
作者:Anil Kumar、Anil K. Pal、Rishi D. Anand、Tej V. Singh、Paloth Venugopalan
DOI:10.1016/j.tet.2011.08.083
日期:2011.10
The nucleophilic fluorination of 1,2,2-triaryl-2-hydroxyethanones by fluoride ion has been carried out usingpyridiniumpoly(hydrogenfluoride) (PPHF) to give 1,2,2-triaryl-2-fluoroethanones in fairly good yield. The presence of electron withdrawing group (EWG), such as –COAr at the carbon bearing hydroxyl group facilitates such nucleophilic fluorination. The intermediacy of bridged oxiranyl ion and
Friedel-Crafts Arylation of α-Hydroxy Ketones: Synthesis of 1,2,2,2-Tetraarylethanones
作者:Anil Kumar、Tej V. Singh、Sajesh P. Thomas、Paloth Venugopalan
DOI:10.1002/ejoc.201403438
日期:2015.2
Friedel-Crafts arylation of a-hydroxy ketones such as 2-hydroxy- 1,2,2-triarylethanones has been achieved with a variety of arenes and heteroarenes in the presence of Lewis or Bronsted acids. Both sterically hindered and unhindered 1,2,2,2-tetrarylethanones are formed in good to excellent yields by using a stoichiometric amount of triflic acid. The intermediacy of an a-keto carbenium ion has been proposed
Transition-Metal-Free and Selective Deconstructive Carbonyl Olefination of α-Hydroxy Ketones: A Complementary Approach to Knoevenagel Reaction
作者:Anil Kumar、Sandeep Sandeep、Vaneet Saini、Chayawan Chayawan、Ganga R. Chaudhary、Paloth Venugopalan
DOI:10.1055/a-2114-7802
日期:2023.10
While the carbonylolefination has been extensively studied and well documented, use of α-hydroxy ketones as precursors for the carbonylolefination is not reported, till date. Herein, a transition-metal-free and selective Knoevenagel-type deconstructive carbonylolefination of α-hydroxy ketones using arylacetonitriles under mild reaction conditions is presented. The reaction affords valuable scaffolds
Indium(III) bromide catalyzed direct azidation of α-hydroxyketones using TMSN3
作者:Anil Kumar、Ramesh K. Sharma、Tej V. Singh、Paloth Venugopalan
DOI:10.1016/j.tet.2013.10.055
日期:2013.12
The direct catalytic azidation of 2-hydroxy-1,2,2-triarylethanones occurs at room temperature using 2 mol % of InBr3 as Lewis acid and TMSN3 as soluble azide source. 2-Azido-1,2,2-triarylethanones have been isolated in excellent yields. The role of aryl group and stereoelectronic factors indicate that the mechanism may involve the formation of a stable carbenium ion towards azidation. (C) 2013 Elsevier Ltd. All rights reserved.