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Rhenium enolates aldol reactions

Cyclic cobalt-acyl complexes can be deprotonated, and subsequent reaction of these enolates with aldehydes gives predominantly the anti/threo product (Scheme 63). Rhenium-acyl complexes can be deprotonated in the same manner. These lithium enolates can be alkylated or can react with [M(CO)5(OTf)] (M = Re, Mn) to give the corresponding enolates (Scheme Many transition metal enolates of type (21) or (22) are known, - but only a few have shown normal enolate behavior , e.g. aldol reaction, reaction with alkyl halides, etc. Particularly useful examples have been developed by Molander. In a process analogous to the Reformatsky reaction, an a-bromo ester may be reduced with Smia to provide excellent yields of condensation products (Scheme 65) which are generated through intermediacy of a samarium(III) enolate. ... [Pg.127]

The enolates (48) and (49) of the transition metals tungsten, rhenium and molybdenum can be successfully prepared by the nucleophilic displacement of a-chloro ketones and a-chloro esters with the appropriate transition metal anion (Scheme 6). They are isolated as C-bound enolate derivatives and, except for the rhenium enolate (49), do not undergo thermal aldol additions to benzaldehyde. However, Bergman and Heathcock et al. have found that an aldol reaction of complex (48) with benzaldehyde can occur on irradiation via the rearranged q -oxaallyl derivative (50), where the metal aldolate (51) can then be... [Pg.312]


See other pages where Rhenium enolates aldol reactions is mentioned: [Pg.8]    [Pg.127]    [Pg.225]   
See also in sourсe #XX -- [ Pg.2 , Pg.312 ]

See also in sourсe #XX -- [ Pg.312 ]

See also in sourсe #XX -- [ Pg.312 ]

See also in sourсe #XX -- [ Pg.2 , Pg.312 ]

See also in sourсe #XX -- [ Pg.312 ]




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Enolates aldol reactions

Enols aldol reactions

Rhenium , reaction

Rhenium enolates

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