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
Metal-Free Azidation of α-Hydroxy Esters and α-Hydroxy Ketones Using Azidotrimethylsilane
作者:Xiao-Ping Yin、Lei Zhu、Jian Zhou
DOI:10.1002/adsc.201701345
日期:2018.3.20
We herein report a commercially available perchloric acid catalyst capable of catalyzing the azidation of α‐hydroxy esters, α‐hydroxy ketones and taddols using azidotrimethylsilane in dichloromethane at room temperature. Various substituted tertiary alcohols are well tolerated in this reaction. Cα‐tetrasubstituted α‐amino acidderivatives were prepared by one‐pot sequential azidation and hydrogenation
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