75599-82-5Relevant academic research and scientific papers
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.
Vinyl Selenides and Selenoxides: Preparation, Conversion to Lithium Reagents, Diels-Alder Reactivity, and Some Comparisons with Sulfur Analogues
Reich, Hans J.,Willis, William W.,Clark, Peter D.
, p. 2775 - 2784 (2007/10/02)
A variety of aryl vinyl selenides are prepared by reaction of vinyl Grignard reagents with aryl selenyl bromides or by reductive elimination of the adducts of lithiums with carbonyl compounds.Deprotonation of phenyl vinyl selenide is achieved with LDA at -78 deg C in THF.Vinyl selenides with β-alkyl groups require LiTMP and warmer temperatures (-50 deg C) for complete deprotonation.Allylic lithium reagents were obtained from 1-propenyl and 2-methyl-1-propenyl selenides whereas 1-butenyl or 3-methyl-1-butenyl selenides gave vinyl lithium reagents.Reaction with electrophiles proceeds in good to excellent yield.Primary halides require HMPA to react well.Unhindered carbonyl compounds react without enolization.Deprotonation with LDA is shown to be reversible, and during competitive deprotonation studies with LDA, aryl vinyl sulfides are found to be thermodynamically less acidic than aryl vinyl selenides (KS/Se=0.21 for phenyl vinyl and 0.3 for m-(trifluoromethyl)phenyl vinyl).Deprotonation with LiTMP is shown to be irreversible, and competitive deprotonation studies showed vinyl selenide to be kinetically more acidic as well S/Se=0.37 (phenyl vinyl),0.42 (m-(trifluoromethyl)phenyl vinyl)>.Most studies have shown sulfur compounds to be more acidic. m-(Trifluoromethyl)phenyl allyl sulfide as expected, is more acidic than selenium compound (kS/Se=3.8).Vinyl selenoxides can be prepared with m-chloroperbenzoic acid.They are not thermally stable enough to serve as acetylene equivalents in Diels-Alder reactions.Phenyl vinyl selenide gives a Diels-Alder addition product with 1,4-diphenylisobenzofuran but failed to give cycloaddition products with less reactive dienes.Phenyl vinyl selenoxide does not give a useful yield of lithium reagent upon reaction with amide bases.
