Cyano Diels−Alder and Cyano Ene Reactions. Applications in a Formal [2 + 2 + 2] Cycloaddition Strategy for the Synthesis of Pyridines
作者:Takeo Sakai、Rick L. Danheiser
DOI:10.1021/ja106901u
日期:2010.9.29
Two metal-free, formal [2 + 2 + 2] cycloaddition strategies for the construction of polycyclic pyridine derivatives are described that proceed via pericyclic cascade mechanisms featuring the participation of unactivated cyano groups as enophile and dienophile cycloaddition partners.
Formal total synthesis of coriolin has been accomplished on the basis of a [3+2] cycloaddition reaction of a vinylsulfide with 3-(methylthio)-2-siloxyallyl cation. A five-membered vinylsulfine as a C ring unit was prepared in five steps from commercially available compounds. The first [3+2] cycloaddition reaction gave the BC ring intermediate, which was then converted into a bicyclic vinylsulfide in
unit (S)-7 gave bicyclic ketones 8 and 9, which were easily converted into vinyl sulfide 11. Stereoselective construction of the A-ring was achieved by the second [3+2] cycloaddition reaction of the BC-ring unit. New methods for introduction of the oxygen functional groups to the triquinane skeleton were also developed for the last stages of the total synthesis. Thus, the C7 hydroxyl group was introduced
N,N-disubstituted 4-amino-piperidines of the general Formula (I) are inhibitors of the uptake of serotonin and/or norepinephrine and/or dopamine. As such, they may be useful for the treatment of disorders of the central and/or peripheral nervous system.