19135-08-1Relevant articles and documents
Mercury-free preparation and selective reactions of propargyl (and propargylic) grignard reagents
Acharya, Hukum P.,Miyoshi, Kei,Kobayashi, Yuichi
, p. 3535 - 3538 (2007)
ZnBr2 was found to catalyze formation of propargyl and propargylic Grignard reagents, and thus put an end to the standard method using a mercury catalyst. The Grignard reagents were submitted to addition reaction with carbonyl compounds and allylation with the cyclic monoacetate to afford the propargyl-type products selectively. Furthermore, the product from the monoacetate was transformed to an acetylene analogue of 2-(5,6-epoxyisoprostane A2)phosphorylcholines.
One-Pot γ-Lactonization of Homopropargyl Alcohols via Intramolecular Ketene Trapping
Yamane, Daichi,Tanaka, Haruna,Hirata, Akihiro,Tamura, Yumiko,Takahashi, Daichi,Takahashi, Yusuke,Nagamitsu, Tohru,Ohtawa, Masaki
supporting information, p. 2831 - 2835 (2021/05/05)
A one-pot γ-lactonization of homopropargyl alcohols via an alkyne deprotonation/boronation/oxidation sequence has been developed. Oxidation of the generated alkynyl boronate affords the corresponding ketene intermediate, which is trapped by the adjacent hydroxy group to furnish the γ-lactone. We have optimized the conditions as well as examined the substrate scope and synthetic applications of this efficient one-pot lactonization.
One-pot, regioselective synthesis of homopropargyl alcohols using pro-pargyl bromide and carbonyl compound by the mg-mediated reaction under solvent-free conditions
Devaramani, Samrat,Li, Shunxi,Ma, Xiaofang,Xu, Daqian,Zhao, Guohu
supporting information, p. 438 - 442 (2020/04/21)
The elimination of volatile organic solvents in organic synthesis is the most important goal in “Green” chemistry. We report a simple, efficient and facile method for the addition of progargyl bromide to carbonyl compounds using Mg metal as a mediator under solvent-free conditions which could regioselectively generate homopropargyl alcohols efficiently in good to excellent yields. The procedure has advantages such as short reaction time, operationally simple, excellent product yields, high regioselectivity and organic solvent-free.
CpTiCl2, an Improved Titanocene(III) Catalyst in Organic Synthesis
Roldan-Molina, Esther,Padial, Natalia M.,Lezama, Luis,Oltra, J. Enrique
, p. 5997 - 6001 (2018/11/23)
Preparation, EPR analysis, and advantages in green organic chemistry of CpTiCl2, an improved single-electron transfer catalyst, are reported. Under mild conditions, this organometallic complex provides excellent yields of homoallylic and homopropargylic alcohols in Barbier-type allylation and propargylation reactions. Moreover, in the presence of a bidentate BOX ligand, Barbier-type cyclization reactions catalyzed by CpTiCl2 can be carried out in an enantioselective manner.
Zinc Amide Catalyzed Regioselective Allenylation and Propargylation of Ketones with Allenyl Boronate
Yamashita, Yasuhiro,Cui, Yi,Xie, Peizhong,Kobayashi, Shu
supporting information, p. 6042 - 6045 (2016/01/09)
Zinc amide catalyzed, regioselective allenylation and propargylation of ketones with allenyl boronate is reported. Tertiary allenyl and homopropargyl alcohols were obtained, respectively, in high selectivities, from the same starting materials, simply by changing the reaction conditions. The substrate scope was wide. Mechanistic studies suggest that the reactions are controlled under kinetic and thermodynamic conditions.
Efficient synthesis of γ-lactones via gold-catalyzed tandem cycloisomerization/oxidation
Shu, Chao,Liu, Meng-Qi,Sun, Yu-Zhe,Ye, Long-Wu
supporting information, p. 4958 - 4961,4 (2012/12/12)
A novel Au-catalyzed tandem cycloisomerization/oxidation of homopropargyl alcohols was developed. Various γ-lactones can be accessed readily by utilizing this strategy. Notably, the mechanism of this reaction is distinctively different from the related Ru-catalyzed reactions where the ruthenium vinylidene intermediate was proposed.
Efficient synthesis of γ-lactones via gold-catalyzed tandem cycloisomerization/oxidation
Shu, Chao,Liu, Meng-Qi,Sun, Yu-Zhe,Ye, Long-Wu
supporting information, p. 4958 - 4961 (2013/01/15)
A novel Au-catalyzed tandem cycloisomerization/oxidation of homopropargyl alcohols was developed. Various γ-lactones can be accessed readily by utilizing this strategy. Notably, the mechanism of this reaction is distinctively different from the related Ru-catalyzed reactions where the ruthenium vinylidene intermediate was proposed.
A new synthesis of γ-butyrolactones via AuCl3- or Hg(II)-catalyzed intramolecular hydroalkoxylation of 4-bromo-3-yn-1-ols
Reddy, Maddi Sridhar,Kumar, Yalla Kiran,Thirupathi, Nuligonda
scheme or table, p. 824 - 827 (2012/04/05)
An efficient conversion of 4-bromo-3-yn-1-ols to γ-butyrolactones via AuCl3-catalyzed electrophilic cyclization (hydroxyl-assisted regioselective hydration) in wet toluene is described. Various secondary and tertiary alcohols including benzylic systems were found to be equally reactive with moderate to excellent yields obtained in all cases.
One-pot, solvent-free allylation or propargylation of carbonyl compounds mediated by the in situ generated Zn-Ag couple
Yu, Changquan,Yang, Jian,Xia, Lingjie,Lu, Xiuyang
experimental part, p. 2484 - 2486 (2012/08/27)
Zn-Ag couple which was in situ generated by zinc being oxidized with catalytic silver acetate was successfully applied to the one-pot and solvent-free allylation or propargylation of carbonyl compounds, in which high yields, regioselective addition, waste minimization and simple operation can be achieved.
Stereoselective synthesis of tertiary ethers through geometric control of highly substituted oxocarbenium ions
Liu, Lei,Floreancig, Paul E.
supporting information; experimental part, p. 5894 - 5897 (2010/12/18)
Fully substituted, fully controlled I The geometries of 1,1-disubstituted oxocarbenium ions and the conformations of oxocarbenium ions that contain a tertiary stereocenter can be predicted based on simple models. These models have been applied to highly stereoselective syntheses of tetrahydropyran derivatives that contain tertiary ethers (see scheme; RL, Rs, and RN represent large, small, and nucleophilic groups, respectively). (Figure Presented)
