75814-57-2Relevant academic research and scientific papers
Alkene Synthesis by Photo-Wolff-Kischner Reaction of Sulfur Ylides and N-Tosylhydrazones
Gao, Pan-Pan,Yan, Dong-Mei,Bi, Ming-Hang,Jiang, Min,Xiao, Wen-Jing,Chen, Jia-Rong
supporting information, p. 14195 - 14201 (2021/09/20)
A visible-light-driven and room temperature photo-Wolff-Kischner reaction of sulfur ylides and N-tosylhydrazones has been developed for the first time to provide modular access to alkene synthesis. The high functional group tolerance and broad substrate scope were demonstrated by more than 60 examples. Both E- and Z-olefinic stereochemistry in the products could be controlled with excellent stereoselectivity. A series of mechanistic studies support that the reaction should proceed through a radical-carbanion crossover pathway, specifically involving addition of photo-generated sulfur ylide radical cations to N-tosylhydrazones to form carbanions and subsequent Wolff-Kischner process.
Selective Construction of C?C and C=C Bonds by Manganese Catalyzed Coupling of Alcohols with Phosphorus Ylides
Liu, Xin,Werner, Thomas
, p. 1096 - 1104 (2020/12/31)
Herein, we report the manganese catalyzed coupling of alcohols with phosphorus ylides. The selectivity in the coupling of primary alcohols with phosphorus ylides to form carbon-carbon single (C?C) and carbon-carbon double (C=C) bonds can be controlled by the ligands. In the conversion of more challenging secondary alcohols with phosphorus ylides the selectivity towards the formation of C?C vs. C=C bonds can be controlled by the reaction conditions, namely the amount of base. The scope and limitations of the coupling reactions were thoroughly evaluated by the conversion of 21 alcohols and 15 ylides. Notably, compared to existing methods, which are based on precious metal complexes as catalysts, the present catalytic system is based on earth abundant manganese catalysts. The reaction can also be performed in a sequential one-pot reaction generating the phosphorus ylide in situ followed manganese catalyzed C?C and C=C bond formation. Mechanistic studies suggest that the C?C bond was generated via a borrowing hydrogen pathway and the C=C bond formation followed an acceptorless dehydrogenative coupling pathway. (Figure presented.).
Acid-promoted olefination of ketones by an iron(III) porphyrin complex
Chen, Ying,Huang, Lingyu,Zhang, X. Peter
, p. 2493 - 2496 (2007/10/03)
(Matrix presented) The acid-promoted olefination of unactivated ketones with diazo reagents in the presence of triphenylphosphine can be catalyzed by the commercially available iron(III) porphyrin complex Fe(TPP)Cl. The reactions were effectively carried out under mild conditions in a one-pot fashion with the use of a stoichiometric diazo reagents and substoichiometric benzoic acid. Examples include aromatic, aliphatic, cyclic, and unsaturated ketones with ethyl diazoacetate or tert-butyl diazoacetate.
Peterson Olefination Reaction Using (Trimethylgermyl)acetate. Stereoselective Synthesis of (E)-2-Alkenoic Acid Esters
Inoue, Sumie,Sato, Yoshiro
, p. 347 - 352 (2007/10/02)
Peterson-type reaction of (trimethylgermyl)acetates 1 with aldehydes and ketones 2 gave stereoselectively (E)-2-alkenoic acid esters (E)-4 after stirring at -78 deg C and warming to room temperature.High yields of the reaction intermediates threo- and erythro-3-hydroxy-2-(trimethylgermyl)alkanoic acid esters 3 were obtained when the reaction was quenched at -78 deg C.The paths for conversion of threo-3 and erythro-3 to (E)-4 are discussed.
Wittig-type Reaction of Dimetallated Carbodianion Species as Produced by Zinc Reduction of gem-Polyhalogen Compounds in the Presence of Levis Acids
Takai, Kazuhiko,Hotta, Yuji,Oshima, Koichiro,Nozaki, Hitosi
, p. 1698 - 1702 (2007/10/02)
Treatment of R1COR2 with a suspension prepared from diiodomethane, trimethylaluminium and excess zinc in tetrahydrofuran at room temperature affords olefins R1R2C=CH2 in fair (R1,R2=alkyl) to good (R1=alkyl, R2=H) yields.The ketone methylenation is better carried with another system consisting of CH2Br2-Zn-TiCl4.Ketones and aldehydes are transformed into α-chloro α,β-unsaturated esters or α,β-unsaturated esters in good yields on treatment with methyl trichloroacetate or t-butyl dichloroacetate (ethyl dibromoacetate) in the presence of diethylaluminium chloride and zinc.
