Stereoselective Oxidative Rearrangement of Disubstituted Unactivated Alkenes Using Hypervalent Iodine(III) Reagent
作者:Chandra Bhan Pandey、Tazeen Azaz、Ram Subhawan Verma、Monika Mishra、Jawahar L. Jat、Bhoopendra Tiwari
DOI:10.1021/acs.joc.0c00347
日期:2020.8.7
The stereoselective oxidative rearrangement of disubstituted unactivated olefins has been achieved using a hypervalent iodine(III) reagent. The aryl group undergoes 1,2-migration to give tert-α-arylated aldehydes (as acetals). The preparation of these aldehydes/acetals, especially containing a tert-benzylic stereocenter, has remained challenging. This migration-based method provides a complementary
Asymmetric synthesis<i>via</i>stereospecific C–N and C–O bond activation of alkyl amine and alcohol derivatives
作者:Sarah M. Pound、Mary P. Watson
DOI:10.1039/c8cc07093h
日期:——
electrophiles for stereospecific, nickel-catalyzed cross-coupling reactions, as well as the prior art that inspired our efforts. The success of our effort has relied on the use of benzyl ammonium triflates as electrophiles for cross-couplings via C–Nbondactivation and benzylic and allylic carboxylates for cross-couplings via C–O bondactivation. Our work, along with others’ exciting discoveries, has demonstrated
Water-promoted cascade synthesis of α-arylaldehydes from arylalkenes using N-halosuccinimides: an avenue for asymmetric oxidation using Cinchona organocatalysis
作者:Abhishek Sharma、Naina Sharma、Rakesh Kumar、Upendra K. Sharma、Arun K. Sinha
DOI:10.1039/b908717f
日期:——
The direct oxidation of arylalkenes into α-arylaldehydes is achieved for the first time in water without relying on transition metal catalysts, and a novel organocatalytic enantioselective approach is also explored to provide up to 30% ee in initial investigations.
A sequential tetra-n-propylammonium perruthenate (TPAP)–Wittig oxidation olefination protocol
作者:Rachel N. MacCoss、Emily P. Balskus、Steven V. Ley
DOI:10.1016/j.tetlet.2003.08.081
日期:2003.10
A convenient sequential oxidation–olefination protocol is reported using tetra-n-propylammonium perruthenate (TPAP) as oxidant and phosphoniumsalts as olefin source. The oxidation reaction mixture is added directly to the phosphorane facilitating an efficient method for this transformation that avoids work-up of potentially sensitive aldehyde intermediates.
MICROWAVE INDUCED SINGLE STEP GREEN SYNTHESIS OF SOME NOVEL 2-ARYL ALDEHYDES AND THEIR ANALOGUES
申请人:Sinha Arun Kumar
公开号:US20120041234A1
公开(公告)日:2012-02-16
The present invention provides a process for the preparation of some novel 2-aryl and 2,2-diaryl aldehydes and analogues which are privileged intermediates for commercially important nonsteroidal anti-inflammatory drugs including naproxen, flurbiprofen and potent anticancer drug candidates, including phenstatin through a unique single step synthetic methodology utilizing easily available substrates in the form of aryl alkenes as well as environmentally benign aqueous reaction conditions in the form of solvents such as mixtures of water and DMSO or Dioxane and reagents N-bromosuccinimide, N-iodosuccinimide, N-cholorosuccinimide and phase transfer catalyst such as cetyltrimethyl ammonium bromide, N-hexyl ammonium chloride for a reaction time varying from 1 min-30 min, depending upon microwave or conventional heating, without using expensive transition metal catalysts or lewis acids/bases with yield varying from 35-55%, depending upon the solvent and substrate used. The developed method provides a clean and convenient alternative to access a diverse range of medicinally important 2-aryl and 2,2-diaryl aldehyde based scaffolds in lieu of the conventional multistep protocols employing expensive and hazardous transition metal catalysts and lewis acids/bases.