Synthesis of aldehydes by isomerisations
An operationally simple palladium-catalyzed isomerization of highly substituted allylic alcohols and alkenyl alcohols is applicable to a broad range of substrates and displays a wide functional group tolerance. Carbonyl compounds can usually be isolated in high chemical yield. Experimental and computational mechanistic investigations provide evidence for a chain-walking process consisting of repeated migratory insertion/β-H elimination sequences.
E. Larionov, L. Lin, L. Guénée, C. Mazet, J. Am. Chem. Soc., 2014, 136, 16882-16894.
A rhodium complex derived from a planar-chiral bidentate phosphaferrocene ligand serves as an effective catalyst for asymmetric isomerizations of allylic alcohols to aldehydes. The method offers improved yields, scope, and enantioselectivities. The catalyst is air-stable and can be recovered at the end of the reaction.
K. Tanaka, G. C. Fu, J. Org. Chem., 2001, 66, 8154-8159.
DABCO is a suitable catalyst for the isomerization of γ-hydroxy enones in an organocatalytic redox isomerization strategy for the synthesis of 1,4-ketoaldehydes in high yields.
K. Mondal, B. Mondal, S. C. Pan, J. Org. Chem., 2016, 81, 4835-4840.