Enolboration-aldolization, asymmetric

Paterson developed asymmetric enolboration-aldolization involving diisopinocampheylboron triflate (57, 32), He has shown the utility of enolboration for the synthesis of various macrolide molecules. His recently completed target molecules include Concanamycin F (33) and the potential anticancer agent, Discodermolide (34) (Figure 6). 

A review of the current status of the applications of chiral organoboranes derived from a-pinene for the synthesis of fluoroorganic molecules has been made. Our three-pronged approach for the synthesis of asymmetric fluoro-organics involve (i) asymmetric reduction of fluoiinated ketones, (ii) asymmetric allylboration of fluoiinated aldehydes, and (iii) asymmetric enolboration-aldolization of fiuoro-ketones and aldehydes. It appears that the presem e of fluorite atom(s) in the molecule influences the stereoctemi< outcome in asymmetric reduction and asymmetric enolboration-aldolization using cMorodiisopinocampheylborane. 

Enolboration of Ketones and Opening of meso-Epoxides. Methyl alkyl ketones have been successfully enolized by IpciBX (X = OTf or Cl) in the presence of a tertiary amine. The corresponding enolborinates have been used in asymmetric aldol condensations (eq 5). The reagent has also been applied to the enantioselective opening of mcj o-epoxides to form the corresponding nonracemic chlorohydrins (eq 6). ... 

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