1-Vinylpyrroles are formylated by the N,N-dimethylformamide/oxalyl chloride reagent system to give the corresponding 1-vinylpyrrole-2-carbaldehydes in good yields in short reaction times.
A. I. Mikhaleva, A. V. Ivanoc, E. V. Skital'tseva, I. A. Ushakov, A. M. Vasil'tsov, B. A. Trofimov, Synthesis, 2009, 587-590.
Highly regio- and stereoselective reactions of readily available 2-(methoxycarbonyl)-2,3-allenols with oxalyl chloride in the presence of Et3N or DMSO afforded methyl 2-(ethynyl)alk-2(E)-enoates and 2-(1′-chlorovinyl)alk-2(Z)-enoates, respectively, in good yields.
Y. Deng, X. Kin, C. Fu, S. Ma, Org. Lett., 2009, 11, 2169-2172.
"Activated" dimethyl sulfoxide efficiently dehydrogenates hydrazones to the respective diazo compounds at -78°C. Under optimized conditions, simple vacuum filtration provides solutions of pure diazo compounds from which stable diazo species can be isolated in high yield, or that can be directly used in subsequent reactions.
M. I. Javed, M. Brewer, Org. Lett., 2007, 9, 1789-1792.