Addition of lithium carbenoids to isocyanates: a direct access to synthetically useful N-substituted 2-haloacetamides.
The addition of lithium carbenoids to isocyanates provides a versatile access to N-substituted 2-haloacetamides: the reaction tolerates the presence of variously functionalized substituents on the nitrogen atom, including sterically demanding ones and reactive halogens. No erosion of the enantiopurity was observed in the case of optically active isocyanates. One of the substrates prepared has been employed in Charette's type chemoselective addition of a Grignard reagent to access an α-chloroketone.
Department of Drug and Natural Product Synthesis, Faculty of Life Sciences, University of Vienna, Althanstrasse 14, Vienna, A-1090, Austria. vpace@farm.ucm.es.
Vittorio
V
Pace
Laura
L
Castoldi
Wolfgang
W
Holzer
D000081:Acetamides / Q000138:chemical synthesis* / Q000737:chemistry; D006219:Halogens / Q000138:chemical synthesis / Q000737:chemistry; D017953:Isocyanates / Q000737:chemistry*; D008094:Lithium / Q000737:chemistry*; D008697:Methane / Q000031:analogs & derivatives* / Q000737:chemistry
D000081:Acetamides; D006219:Halogens; D017953:Isocyanates; C030011:carbene; D008094:Lithium; D008697:Methane