Categories: N/N Bond Formation >
Synthesis of Diazo Compounds
"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.
The reaction of 1-aryl-2,2,2-trifluorodiazoethanes with alkenes provides trifluoromethyl-substituted cyclopropanes with high diastereoselectivity and enantioselectivity in the presence of an adamantylglycine-derived dirhodium complex Rh2(R-PTAD)4 as catalyst.
J. R. Denton, D. Sukumaran, H. M. L. Davies, Org. Lett., 2007, 9, 2625-2628.