16411-17-9Relevant academic research and scientific papers
Difluoro- and trifluoro diazoalkanes-complementary approaches in batch and flow and their application in cycloaddition reactions
Hock, Katharina J.,Mertens, Lucas,Metze, Friederike K.,Schmittmann, Clemens,Koenigs, Rene M.
supporting information, p. 905 - 909 (2017/08/14)
Herein we report on applications of fluorinated diazoalkanes in cycloaddition reactions, with the emphasis on studying subtle differences between diverse fluorinated diazo compounds. These differences led to two major synthetic protocols in batch and flow that allow the safe and scalable synthesis of fluoroalkyl-, sulfone-substituted pyrazolines.
Palladium-Catalyzed Synthesis of Aryl Vinyl Sulfides via 1,3-Oxathiolanes As Vinyl Sulfide Surrogates
Schmink, Jason R.,Dockrey, Summer A. Baker,Zhang, Tianyi,Chebet, Naomi,Van Venrooy, Alexis,Sexton, Mary,Lew, Sarah I.,Chou, Steffany,Okazaki, Ami
supporting information, p. 6360 - 6363 (2016/12/23)
A nontraditional approach to synthesizing aryl vinyl sulfides is described. 2,2-Diphenyl-1,3-oxathiolane slowly liberates a vinyl sulfide anion under basic conditions. Using a Pd/Xantphos catalyst system to activate a wide range of aryl bromides, this transient sulfide species can be effectively trapped and fed into a traditional Pd0/PdII catalytic cycle. Scope and limitations of the methodology are presented along with significant discussion of a competitive C-S bond activation by this catalyst system.
Hydrogenative Kinetic Resolution of Vinyl Sulfoxides
Lao, Joan R.,Fernndez-Prez, Hctor,Vidal-Ferran, Anton
supporting information, p. 4114 - 4117 (2015/09/01)
Enantiopure sulfoxides are valuable precursors of organosulfur compounds with broad application in organic and pharmaceutical chemistry. An unprecedented strategy for obtaining highly enantioenriched sulfoxides based on a hydrogenative kinetic resolution using Rh-complexes of phosphine-phosphite ligands as catalysts is reported. After optimization, highly efficient conditions for the kinetic resolution of racemic sulfoxides have been identified. This methodology has been applied to a set of racemic aralkyl or aryl vinyl sulfoxides and allowed the isolation of both recovered and reduced products in excellent yields and enantioselectivities (up to 99% and 97% ee, respectively; 16 examples).
Convenient criterion for the distinction between electrophilic and electron transfer reactions of electron-rich alkenes
Bauld, Nathan L.,Aplin, J. Todd,Yueh, Wang,Endo, Stephanie,Loving, Angie
, p. 15 - 24 (2007/10/03)
Both experimental and theoretical studies confirm that the formation of aryl vinyl ether and aryl vinyl sulfide cation radicals from the corresponding neutral substrates correlates with the Brown σ+ parameters as opposed to Hammett σ values. Peak oxidation potentials for both classes of substrates correlate preferentially with σ+, as do gas-phase ionization energies calculated by both semi-empirical and ab initio methods. In contrast, the protonation energies of the same substrates, which relate to carbocation formation, correlate preferentially with σ values, as do rates of protonation and other electrophilic additions. These observations permit a sharp distinction between electrophilic and electron transfer reactions of these two common classes of electron-rich substrates. Using this criterion, the cycloadditions of tetracyanoethylene to these substrates are found to proceed via an electrophilic mechanism, rather than by a previously proposed electron transfer mechanism.
A non-outer sphere mechanism for the ionization of aryl vinyl sulfides by triarylaminium salts
Bauld, Nathan L.,Aplin, J. Todd,Yueh, Wang,Loinaz, Ainhoa
, p. 11381 - 11389 (2007/10/03)
Evidence is presented that the formation of aryl vinyl sulfide cation radicals from the corresponding neutral precursors via reaction with tris(4- bromophenyl)aminium hexachloroantimonate in the context of a cation radical Diels-Alder addition to 1,3-cyclopentadiene does not occur via outer sphere electron transfer but by a mechanism involving strong covalent interaction between the aminium salt acting as an electrophile and the aryl vinyl sulfide substrate acting as a nucleophile.
