InBr<sub>3</sub>: A Versatile Catalyst for the Different Types of Friedel−Crafts Reactions
作者:Ponnaboina Thirupathi、Sung Soo Kim
DOI:10.1021/jo9014613
日期:2009.10.16
Mild and efficient InBr3-catalyzed Friedel−Crafts alkylation of heteroaromatic or electron-rich aromatic compounds with α-amido sulfones at room temperature in CH2Cl2 has been developed. The products undergo further Friedel−Crafts alkylation with heteroaromatic or electron-rich aromatic compounds leading to unsymmetrical or bis-symmetrical triaryl methanes in good yield. α-Amido sulfones are employed
Bismuth Triflate-Catalyzed Addition of Allylsilanes to N-Alkoxycarbonylamino Sulfones: Convenient Access to 3-Cbz-Protected Cyclohexenylamines
作者:Thierry Ollevier、Zhiya Li
DOI:10.1002/adsc.200900710
日期:2009.12
Bismuth triflate was found to be an efficient catalyst in the Sakurai reaction of allyltrimethylsilanes with N-alkoxycarbonylaminosulfones. The reaction proceeded smoothly with a low catalyst loading of Bi(OTf)3⋅4 H2O (2–5 mol%) to afford the corresponding protected homoallylic amines in very good yields (up to 96%). A sequential allylation reaction followed by ring-closing metathesis delivers 6–8
Bismuth triflate was found to be an efficient catalyst in the Mannich-typereaction of silylenolates with N-alkoxycarbonylamino sulfones. The reaction proceeded smoothly with a low catalyst loading of bismuth triflate (0.5–1.0 mol %) to afford the corresponding protected β-aminocarbonyl compound in very good yields (up to 96 %).
Synthetic application of in situ generation of N-acyliminium ions from α-amido p-tolylsulfones for the synthesis of α-amino nitriles
作者:Santosh T. Kadam、Ponnaboina Thirupathi、Sung Soo Kim
DOI:10.1016/j.tet.2010.01.010
日期:2010.2
N-acyliminium ions, which undergo the nucleophilic addition of trimethylsilyl cyanide (TMSCN) to provide the N-protected α-aminonitriles in very good yield. A variety of α-amido p-tolylsulfones were prepared from aromatic as well as aliphatic aldehydes for the synthesis of α-aminonitriles.
General and Facile Synthesis of 1,2-Amino Alcohols
作者:Yong Hae Kim、Doo Young Jung、Chang Hong Ko
DOI:10.1055/s-2004-822926
日期:——
Facile preparation of 1,2-amino alcohols has been achieved by the reaction of benzyloxymethyl lithium with imines, which are generatedfromα-amidosulfones and benzyloxymethyl lithium in situ at -78 °C in THF.