91873-75-5Relevant academic research and scientific papers
Generation of 1,2-oxathiolium ions from (arysulfonyl)- and (arylsulfinyl)allenes in Br?nsted acids. NMR and DFT study of these cations and their reactions
Lozovskiy, Stanislav V.,Ivanov, Alexander Yu.,Khoroshilova, Olesya V.,Vasilyev, Aleksander V.
, p. 2897 - 2906 (2018/12/13)
In strong Br?nsted acids (CF3SO3H, FSO3H, D2SO4), (arysulfonyl)allenes (ArSO2-CR1=C=CR2R3) and (arylsulfinyl)allenes (ArSO-CR1=C=CR2R3) undergo cyclization into the corresponding stable 1,2-oxathiolium ions, which were studied by means of NMR and DFT calculations. Quenching of solutions of these cations with low nucleophilic media, aqueous HCl, leads to their deprotonation with a stereoselective formation of (arysulfonyl)butadienes (for instance, ArSO2-CR1=C-C(Me)=CH2, for R2 = R3 = Me, yields of 87-98%). Reactions of (arysulfonyl)allenes in the system TfOH (0.1 equiv)-HFIP (hexafluoropropan-2-ol) followed by hydrolysis give rise to allyl alcohols (ArSO2-CR1=CH-C(OH)R2R3, yields of 78-99%). Reflux of solutions of (arysulfonyl)allenes in the presence of TfOH (1 equiv) in 1,2-dichlorobenzene leads to the cyclization into thiochromene 1,1-diox-ides in high yields. Under the action of TfOH or AlX3 (X = Cl, Br) followed by hydrolysis of reaction mixtures, (arylsulfinyl)allenes give allyl alcohols (ArSO2-CR1=CH-C(OH)R2R3). Plausible reaction mechanisms have been proposed for all studied reactions.
[2,3] sigmatropic rearrangement of propargylic sulfinates by a pale Ag1-USY zeolite and silver salts
Hamptona, Carissa S.,Harmata, Michael
supporting information, p. 549 - 552 (2015/02/19)
The sigmatropic rearrangement of propargylic sulfinates to allenic sulfones is catalyzed by the silver cation. The Ag1-USY zeolite, as well as non-coordinating silver salts, lead to essentially quantitative yields of the corresponding allenic s
Synthesis of thiophenes from allenyl sulfones involving α,β-unsaturated sulfines as intermediates
Linden, Johannes B. van der,Asten, Peter F. T. M. van,Braverman, Samuel,Zwanenburg, Binne
, p. 51 - 60 (2007/10/02)
The synthesis of thiophenes starting from allenyl sulfones, via intermediate formation of α,β-unsaturated sulfines, is described.The allenyl sulfones were synthesized by a -sigmatropic rearrangement of appropriately substituted prop-2-ynyl sulfinates
Preparation of Allenic Sulfones and Allenes from the Selenosulfonation of Acetylenes
Back, Thomas G.,Krishna, M. Vijaya,Muralidharan, K. Raman
, p. 4146 - 4153 (2007/10/02)
β-(Phenylseleno)vinyl sulfones 2 are readily obtained from the free-radical selenosulfonation of acetylenes.Compounds 2 isomerize to allyl sulfones 4 under base-catalyzed conditions in nearly quantitative yield, with high stereoselectivity favoring the Z configuration.Allyl sulfones 4 afford generally high yields of allenic sulfones 1 when subjected to oxidation with m-chloroperbenzoic acid or tert-butyl hydroperoxide, followed by selenoxide syn-elimination.The sulfone-stabilized anion intermediates in the isomerizations of 2 to 4 can be alkylated, deuterated,or silylated in the α-position prior to oxidation, providing allenic sulfones with an additional α-substituent.In some cases, spontaneous elimination of the phenylseleno group occurred, producing the allenic sulfone without the need for an oxidation step.Desulfonylation of allyl sulfones 4f, 4c, and 25 with sodium amalgam afforded vinyl selenides that were converted to allenes in moderate to good yields by oxidation-elimination.The copper catalyzed coupling of allyl sulfones 4 with Grignard reagents comprises an alternative route to vinyl selenide precursors of allenes.These procedures permit the synthesis of various α- and γ-substituted allenic sulfones and allenes from acetylenes.
Studies on the Addition of Allyl Oxides to Sulfonylallenes. Preparation of Highly Substituted Allyl Vinyl Ethers for Carbanionic Claisen Rearrangements
Denmark, Scott E.,Harmata, Michael A.,White, Kathleen S.
, p. 4031 - 4042 (2007/10/02)
Thirty-five allyl vinyl ethers bearing an arylsulfonyl anion-stabilizing group have been prepared by addition of allylic alkoxides to (arylsulfonyl)allenes.The allyl vinyl ethers are produced as either β,γ-unsaturated or α,β-unsaturated sulfones depending upon the substitution pattern of the allene and the reaction conditions.A wide variety of substitution patterns are available by using this method.Factors that control the position and stereochemistry of the vinyl ether double bond are discussed.
CARBANION-ACCELERATED CLAISEN REARRANGEMENTS 3. VICINAL QUATERNARY CENTERS
Denmark, Scott E.,Harmata, Michael A.
, p. 1543 - 1546 (2007/10/02)
The preparation and Claisen rearrangement of highly substituated allyl vinyl ethers is described.It is demonstrated that the thermal and anionic versions of the Claisen rearrangement are capable of creating vicinal quaternary centers.
