82720-22-7Relevant academic research and scientific papers
Transition-Metal-Free Radical Hydrotrifluoromethylation of Alkynes
Matcha, Kiran,Antonchick, Andrey P.
supporting information, p. 309 - 312 (2019/01/24)
A combination of readily available and bench-stable CF3SO2Na and tBuOOH was efficiently used for hydrotrifluoromethylation of alkynes. An excellent trans-selectivity was demonstrated in the synthesis of alkenes. The developed mild reaction conditions allow the supression of the competing Meyer–Schuster-type rearrangement.
Neighboring Carbonyl Group Assisted Oxyacetoxylation of Propargylic Carboxylates with Retention of Chirality under Metal Free Condition
Pradhan, Tapas R.,Mohapatra, Debendra K.
, p. 3605 - 3611 (2019/07/04)
A metal-free oxyacetoxylation method of primary, secondary and tertiary propargylic carboxylates with retention of chirality was presented. The reaction proceeds through the intramolecular nucleophilic attack of the neighboring carbonyl group on an alkynyliodonium intermediate. The process is general with broad substrate scope and is amenable for application to a variety of propargyl carboxylates including those obtained from natural products. Insight into the mechanistic pathway by isotopic labelling (using H2O18 and D2O) and controlled experiments confirmed. (Figure presented.).
Heterogeneous Acid-Catalyzed Racemization of Tertiary Alcohols
G?rbe, Tamás,Lihammar, Richard,B?ckvall, Jan -E.
supporting information, p. 77 - 80 (2017/12/07)
Tertiary alcohols are important structural motifs in natural products and building blocks in organic synthesis but only few methods are known for their enantioselective preparation. Chiral resolution is one of these approaches that leaves one enantiomer (50 % of the material) unaffected. An attractive method to increase the efficiency of those resolutions is to racemize the unaffected enantiomer. In the present work, we have developed a practical racemization protocol for tertiary alcohols. Five different acidic resin materials were tested. The Dowex 50WX8 was the resin of choice since it was capable of racemizing tertiary alcohols without any byproduct formation. Suitable solvents and a biphasic system were investigated, and the optimized system was capable of racemizing differently substituted tertiary alcohols.
Bronsted acid mediated nitrogenation of propargylic alcohols: An efficient approach to alkenyl nitriles
Huang, Xiaoqiang,Jiao, Ning
supporting information, p. 4324 - 4328 (2014/06/23)
A novel and efficient approach to alkenyl nitriles from readily available propargylic alcohols has been developed. This nitrogenation reaction is transition-metal-free and could be conducted under air at ambient temperature, which makes this protocol promising and practical. Moreover, NH4Br is disclosed as an efficient additive to promote the stereoselectivity of this reaction. the Partner Organisations 2014.
Pd(II)-catalyzed highly regio-and stereoselective assembly of C-C double bonds: An efficient method for the synthesis of 2,4-dihalo-1,3,5-trienes from alkynols
Jiang, Huanfeng,Gao, Yang,Wu, Wanqing,Huang, Yubing
supporting information, p. 238 - 241 (2013/03/13)
A highly efficient method for the synthesis of 2,4-dihalo-1,3,5-trienes from alkynols was developed. This chemistry allows access to multiple conjugated double bonds in a single step with high stereoselectivity.
Au-catalyzed formation of functionalized quinolines from 2-alkynyl arylazide derivatives
Gronnier, Colombe,Boissonnat, Guillaume,Gagosz, Fabien
, p. 4234 - 4237 (2013/09/12)
A new method for converting 2-alkynyl arylazide derivatives into functionalized polysubstituted quinolines following a gold-catalyzed 1,3-acetoxy shift/cyclization/1,2-group shift sequence has been developed. This transformation proceeds under mild reaction conditions, is efficient, and tolerates a large variety of functional groups.
Gold-catalyzed regioselective hydration of propargyl acetates assisted by a neighboring carbonyl group: Access to α-acyloxy methyl ketones and synthesis of (±)-actinopolymorphol B
Ghosh, Nayan,Nayak, Sanatan,Sahoo, Akhila K.
, p. 500 - 511 (2011/04/17)
A general atom-economical approach for the synthesis of α-acyloxy methyl ketone is demonstrated through regioselective hydration of a wide range of propargyl acetates. Readily available catalyst comprising of 1% Ph 3PAuCl and 1% AgSbF6 in dioxane-H2O efficiently hydrolyzes the terminal alkynes of the propargyl acetate in the absence of acid promoters at ambient temperature within a short time. Effective regioselective hydration is facilitated by the neighboring carbonyl group as demonstrated through 18O-labeling study. Compatibility of functional moieties and tolerance to various acid-labile protecting groups are observed. The catalytic condition is also suitable to perform hydration of TMS-substituted propargyl acetates, even though it requires prolonged reaction time for completion. Stereointegrity of the propargylic acetate is preserved during the hydration. The robustness of the system is successfully demonstrated through gram scale preparation of the product in nearly quantitative yield. The common α-acyloxy methyl ketone is transformed to 1,2-diol and 1,2-amino alcohol derivatives. Synthesis of actinopolymorphol B is achieved for the first time involving hydration of the propargyl acetate as the key step.
