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 %).
The first catalytic Sakurai reaction of N-alkoxycarbonylamino sulfones with allyltrimethylsilane
作者:Thierry Ollevier、Zhiya Li
DOI:10.1039/b613331b
日期:——
We report the firstcatalytic Sakurai reaction of N-alkoxycarbonylamino sulfones with allylsilanes. The allylation reaction of N-alkoxycarbonylamino phenylsulfones with allyltrimethylsilane proceeded smoothly with low catalyst loading of bismuth triflate (2.0 mol%) to afford the corresponding protected homoallylic amines in moderate to very good yields (up to 96%).
Stereocontrolled synthesis of hydroxyethylamine isosteres via chiral sulfoxide chemistry
作者:Cristina Pesenti、Alberto Arnone、Paolo Arosio、Massimo Frigerio、Stefano V. Meille、Walter Panzeri、Fiorenza Viani、Matteo Zanda
DOI:10.1016/j.tetlet.2004.04.160
日期:2004.6
A novel synthesis of enantiopure hydroxyethylamine isosteres has been developed. Reaction of lithiated beta-sulfinyl-ethylamines 3 with N-Cbz-irnines generated in situ from alpha-amino-sulfones 4 afforded in good to excellent yields and moderate stereocontrol the 2-sulfinyl-1,3-diamines 2. The latter were submitted to the nonoxidative Pummerer reaction (NOPR) in CH2Cl2, that produced the target compounds 1 in very good yields with inversion Of Configuration. In some cases, the use of acetonitrile as solvent resulted in a double-inversion pathway, leading for example to the oxazolidinone 5. The total synthesis of an epimer of Saquinavir has been achieved by this method. (C) 2004 Elsevier Ltd. All rights reserved.