A novel organocatalytic dual activation strategy is reported
for an efficient synthesis of the versatile synthons (2E)-1-aryl/heteroaryl/styryl-3-(dimethylamino)prop-2-en-1-ones
and α-(E)-[(dimethylamino)methylene]cycloalkanones.
2-Guanidinoacetic acid (10 mol%) serves as an ambifunctional
organocatalyst for the reaction of various aryl/heteroaryl/styryl
methyl ketones and cyclic ketones having an α-methylene
moiety with N,N-dimethylformamide
dimethyl acetal at 100 ˚C for 1-3 hours under
solvent-free conditions to afford the corresponding (2E)-3-(dimethylamino)prop-2-en-1-ones
in 72-95% yields.
2-guanidinoacetic acid - organocatalyst - dual
activation - 3-(dimethylamino)propenones - aryl
methyl ketone -
N,N-dimethylformamide dimethyl
acetal
