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Halogenation Henry reaction

Fluoromethyl ketones are one of the most widely used classes of peptidyl a-fluoroalkyl ketones, second only to trifluoromethyl ketones. Peptidyl fluoromethyl ketones are very effective as irreversible inhibitors of cysteine proteases the first reported use of a fluoromethyl ketone compound was the use of Z-Phe-Ala-CH2F as an irreversible inhibitor of cathepsin BJ2,31 Today, many lysine and arginine derivatives have been synthesized as potential inhibitors for trypsin and trypsin-like enzymesJ3 There are four basic methods for the synthesis of peptide fluoromethyl ketones (1) the reaction of HF with peptide diazomethyl ketones (Section 15.1.4.1.1), (2) a halogen-exchange reaction with a chloro-, bromo-, or iodomethyl ketone (Section 15.1.4.1.2), (3) a Henry nitro-aldol condensation reaction (Section 15.1.4.1.3), and (4) a modified Dakin-West acylation reaction (Section 15.1.4.1.4). [Pg.226]

This model is based on the exploration of halogenation reactions studied by Henry in the context of Wacker-type reactions [77]. As for palladium an oxidation state higher than - -II can in principle not be induced with an oxidant such as divalent copper, interaction between copper salts and a palladium center should induce electron transfer, which, consequently, should weaken the palladium-carbon bond. The resulting electrophilic character at carbon should make this center susceptible to nucleophilic attack. [Pg.1288]


See other pages where Halogenation Henry reaction is mentioned: [Pg.341]    [Pg.323]    [Pg.323]    [Pg.28]    [Pg.373]    [Pg.323]    [Pg.1406]    [Pg.66]    [Pg.697]    [Pg.91]    [Pg.91]    [Pg.459]    [Pg.459]    [Pg.41]    [Pg.459]    [Pg.1]    [Pg.72]    [Pg.1299]    [Pg.509]   
See also in sourсe #XX -- [ Pg.77 , Pg.79 ]




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