In this paper, N-Boc and N-Cbz protected alpha-branched amines are synthesized directly from commercially available aromatic/heteroaromatic compounds, aldehydes, and tert-butyl or benzyl carbamate bearing a variety of substituents. Bismuth(III) triflate is found to be a highly effective catalyst for this one-pot, three-component coupling reaction. In addition, the use of mild reaction conditions, low catalytic loading, easy removal of the N-protective group, and one-step synthesis under open-flask are advantages of the present procedure.
Iodine-catalyzed, one-pot, three-component aza-Friedel–Crafts reaction of electron-rich arenes with aldehyde/carbamate combinations
Iodine is shown to be an efficient catalyst for a one-step, three-component aza-Friedel-Crafts reaction of activated arenes or heteroarenes with benzyl or tert-butyl carbamates in combination with a wide variety of aldehydes in toluene under 'open-flask' and mild conditions. In the presence of 5 mol % of iodine in toluene at room temperature, the reaction gives the corresponding N-CBz or N-Boc protected a-branched amines, selectively, in good to excellent yields. (C) 2012 Published by Elsevier Ltd.
Facile synthesis of nonsymmetrical heteroaryl-substituted triarylmethanes via the FeCl<sub>3</sub>·6H<sub>2</sub>O-catalyzed two-step Friedel–Crafts-type reaction
diarylmethyl carbamate with heteroaromatic compounds under “open-flask” at room temperature was also performed. The two-step reaction was especially useful for the synthesis of functionalized nonsymmetrical heteroaryl-substitutedtriarylmethanes in good yields under an air atmosphere at room temperature.
The acid promoted Petasis reaction of organotrifluoroborates with imines and enamines
作者:Diane E. Carrera
DOI:10.1039/c7cc04397j
日期:——
salts to imine and enamine electrophiles is reported. Use of the pre-activated trifluoroboronate complex bypasses the need for α-hetero substitution on the electrophile component, greatly expanding the scope of the Petasis borono–Mannich reaction. A variety of vinyl, aromatic and heteroaromatic trifluoroborate salts undergo addition with good efficiency under mild reaction conditions. The reaction is amenable