Stereoselective Synthesis of δ-Lactones from 5-Oxoalkanals via One-Pot Sequential Acetalization, Tishchenko Reaction, and Lactonization by Cooperative Catalysis of Samarium Ion and Mercaptan
作者:Jue-Liang Hsu、Jim-Min Fang
DOI:10.1021/jo016058t
日期:2001.12.1
sequence of acetalization, Tishchenko reaction and lactonization. The deliberative use of mercaptan, by comparison with alcohol, is advantageous to facilitate the catalytic cycle. The reaction mechanism and stereochemistry are proposed and supported by some experimental evidence. Such samarium ion/mercaptan cocatalyzed reactions show the feature of remote control, which is applicable to the asymmetric synthesis
Bismuth trichloride as a new efficient catalyst in the aldol reaction
作者:Hidenori Ohki、Makoto Wada、Kin-ya Akiba
DOI:10.1016/s0040-4039(00)80590-0
日期:——
In the presence of a catalytic amount of bismuthtrichloride (5 mol%), silyl enol ethers react with aldehydes at room temperature to give the corresponding aldols in good yields.
Cooperative Catalysis of Samarium Diiodide and Mercaptan in a Stereoselective One-Pot Transformation of 5-Oxopentanals into δ-Lactones
作者:Jue-Liang Hsu、Chao-Tsen Chen、Jim-Min Fang
DOI:10.1021/ol9911526
日期:1999.12.1
[GRAPHICS]We demonstrate a general method for conversion of various 5-oxopentanals to substituted delta-lactones and 1-oxa-2-decalones by the synergistic catalysis of samarium diiodide and 2-propanethiol (or disulfide), The deliberate use of mercaptan is advantageous to facilitate the catalytic cycle, This method shows high stereoselectivities, and an enantioselective procedure is feasible by using the chiral mercaptan (1R,2S)-1 phenyl-2-(N-acetamido)propanethiol as a promoter.
Iron-Catalyzed Oxidation of Tertiary Amines: Synthesis of β-1,3-Dicarbonyl Aldehydes by Three-Component C–C Couplings
作者:Weiping Liu、Jinhua Liu、Daisuke Ogawa、Yasushi Nishihara、Xingwei Guo、Zhiping Li
DOI:10.1021/ol202749x
日期:2011.12.2
beta-1,3-Dicarbonyl aldehydes were synthesized by iron-catalyzed oxidative reactions between 1,3-dicarbonyl compounds and two molecules of tertiary amines in the presence of tert-butyl hydroperoxide (TBHP). alpha,beta-Unsaturated aldehydes generated by tertiary amine oxidation In situ act as key intermediates under mild reaction conditions.
Lewis Acid Catalysis with Cationic Dinuclear Gold(II,II) and Gold(III,III) Phosphorus Ylide Complexes
作者:Benjamin R. Reiner、Mark W. Bezpalko、Bruce M. Foxman、Casey R. Wade
DOI:10.1021/acs.organomet.6b00403
日期:2016.9.12
The.dinuclear gold(II,II) and gold(III,III) complexes [Au-2(mu-PY)(2)(MeCN)(2)]OTf2 (2-OTf2) and [Au-2(mu-PY)(2)(mu-CH2)(MeCN)(2)]OTf2 (3-OTf2) (PY = [(CH2)(2)PPh2](-)) have been synthesized and evaluated as Lewis acid catalysts for Mukaiyama addition and alkyne hydroamination reactions. 2-OTf2 and 3-OTf2 provide similar or improved catalytic activity for these reactions compared to the commonly used gold(I) Lewis acids Ph3PAuOTf and IPrAuOTf. The versatile Lewis acidity of 2-OTf2 was further demonstrated by its superior performance in a cascade reaction involving intramolecular hydroamination followed by intermolecular conjugate addition to generate a 2,3-substituted indole.