Sulfur dioxide mediated one-pot, four-component synthesis of polyfunctional sulfones and sulfonamides, including medium-ring cyclic derivatives
摘要:
In previous papers (Synthesis 2002, 232 and J. Org. Chem. 2004, 69, 6413), we have shown that the hetero-Diels-Alder addition of sulfur dioxide to 1-oxy or 1,3-dioxy- 1,3-dienes generates zwitterions that add to enoxysilanes or allylsilanes giving silyl sulfinates that can be converted in the same pot into polyfunctional sulfones, sulfonamides or sulfonic esters. We are presenting further applications of this method, including the synthesis of new medium-size heterocyclic systems of the type tetrahydro-2H-thiocines and hexahydro-1,2-thiazonine. (c) 2005 Elsevier Ltd, All rights reserved.
Organocatalytic α-trifluoromethylthiolation of silylenol ethers: Batch vs continuous flow reactions
作者:Said Said Abubakar、Maurizio Benaglia、Sergio Rossi、Rita Annunziata
DOI:10.1016/j.cattod.2017.09.013
日期:2018.6
performed under a traditional batch methodology and under continuousflow conditions. In general, yields obtained using the traditional batch process were higher than those observed when the reaction was performed under flow conditions. However, short reaction times, higher productivity and higher space time yields were observed when a flow system process was employed. Preliminary DFT calculations
Asymmetric Electrophilic α-Amination of Silyl Enol Ether Derivatives via the Nitrosocarbonyl Hetero-ene Reaction
作者:David Sandoval、Andrey V. Samoshin、Javier Read de Alaniz
DOI:10.1021/acs.orglett.5b02208
日期:2015.9.18
nitrosocarbonyl hetero-ene reaction is described. The procedure uses a copper-catalyzed aerobic oxidation of a commercially available chiral nitrosocarbonyl precursor (EleNOr) and is operationally simple. The transformation is both high yielding and highly diastereoselective for a range of silyl enol etherderivatives. A variety of synthetically useful postfunctionalization reactions are presented along with
Aqueous Asymmetric Mukaiyama Aldol Reaction Catalyzed by Chiral Gallium Lewis Acid with Trost-Type Semi-Crown Ligands
作者:Hui-Jing Li、Hong-Yu Tian、Yan-Chao Wu、Yong-Jun Chen、Li Liu、Dong Wang、Chao-Jun Li
DOI:10.1002/adsc.200505089
日期:2005.7
generates highly effective chiral gallium Lewis acid catalysts for aqueous asymmetric aldolreactions of aromatic silyl enol ethers with aldehydes. A ligand-acceleration effect was observed. Water is essential for obtaining high diastereoselectivity and enantioselectivity. The p-phenyl substituent in aromatic silyl enol ether (2 h) plays an important role and increases the enantioselectivity up to 95%
Catalytic, Enantioselective Sulfenylation of Ketone-Derived Enoxysilanes
作者:Scott E. Denmark、Sergio Rossi、Matthew P. Webster、Hao Wang
DOI:10.1021/ja506133z
日期:2014.9.17
A catalytic, enantioselective, Lewis base-catalyzed α-sulfenylation of silylenolethers has been developed. To avoid acidic hydrolysis of the silylenolether substrates, a sulfenylating agent that did not require additional Brønstedacid activation, namely N-phenylthiosaccharin, was developed. Three classes of Lewis bases—tertiary amines, sulfides, and selenophosphoramides—were identified as active
Catalytic, Asymmetric Mannich-type Reactions of <i>N</i>-Acylimino Esters: Reactivity, Diastereo- and Enantioselectivity, and Application to Synthesis of N-Acylated Amino Acid Derivatives
the synthesis of biologically important compounds were prepared using this novel catalytic asymmetricMannich-type reaction, and at the same time, absolute and relative stereochemical assignments were made. In addition, it has been revealed that alkyl vinyl ethers reacted with N-acylimino esters in the presence of a catalytic amount of the Cu(II) catalyst to give the corresponding Mannich-type adducts
在催化量的 Cu(OTf)(2)-手性二胺 3e 复合物存在下,N-酰基亚氨基酯与甲硅烷基烯醇醚反应以高产率和高对映选择性提供相应的曼尼希型加合物。各种衍生自酮的甲硅烷基烯醇醚以及酯和硫酯都能顺利反应。在α-取代的甲硅烷基烯醇醚(α-甲基或苄氧基)的反应中,以高产率和高非对映选择性和对映选择性获得了所需的顺式加合物。使用这种新型催化不对称曼尼希型反应制备了几种用于合成生物学上重要化合物的中间体,同时进行了绝对和相对立体化学分配。此外,已经表明,在催化量的 Cu(II) 催化剂存在下,烷基乙烯基醚与 N-酰基亚氨基酯反应,以高产率和高对映选择性得到相应的曼尼希型加合物。这是与烷基乙烯基醚催化不对称曼尼希型反应的第一个例子。基于Cu(II)-手性胺配合物的X射线晶体学分析、PM3计算和FT-IR分析等假设了反应机理、手性催化剂-亲电子配合物的结构以及这些催化不对称反应的过渡态. 最后,(1R,