Gallium(III) Chloride-catalyzed Sakurai Reaction of α-Amido Sulfones with Allyltrimethylsilane: Access to Synthesis of 2,6-Disubstituted Piperidine Alkaloid Derivatives
of N-alkoxycarbonylamino sulfones (α-amidosulfones) with allyltrimethylsilane in the presence of gallium(III) chloride (5 mol %) proceeded smoothly to afford the corresponding protected homoallylamines in high yields (82―96%). As an application of this methodology, two-step synthesis of biologically active natural products, 2,6-disubstituted piperidine alkaloid derivatives was carried out.
An efficient method for the one-pot synthesis of secondary and tertiary N-homoallylic carbamates using catalytic amount of HBF4 center dot OEt2 is described. The reaction proceeded smoothly to afford the corresponding N-homoallylic carbamates in good to high yields. Operationally simple and easily scalable features make this method more practical over existing methods. Use of HBF4 center dot OEt2 as an acid catalyst also proves the catalytic activity of fluorinated acid catalyst in this important organic transformation. (C) 2014 Elsevier B.V. All rights reserved.