Alkaloids ionic hydrogenation

Jacquesy and co-workers884 have reported the stereoselective ionic hydrogenation of Vinca alkaloids to produce the corresponding A R reduced analogs (Scheme 5.92). Mechanistic studies with cyclohexane- 2 showed that deuterium incorporation takes place exclusively at C(20 ). 

SALT. A compound formed by replacement of part or all of the hydrogen of an acid by one (or more) element(s) or radrcal(s) that are essentially inorganic. Alkaloids, amines, pyridines, and other basic organic substances may be regarded as substituted ammonias in this connection. The characteristic properties of salts are the ionic lattice in the solid state and the ability to dissociate completely in solution. The halogen derivatives of hydrocarbon radicals and esters are not regarded as salts in the strict definition of the term,... 

As compounds that are hydrophilic and basic, it is no surprise that alkaloids interact readily with essential biochemical constituents such as proteins, polysaccharides, and nucleic acids, forming hydrogen bonds and ionic bonds. Less obvious reactions may also be relatively common. For example, essential thiol groups of proteins can undergo nucleophilic reactions with positively charged alkaloids, and pi complexes are possible... 

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