Catalytic Enantioselective Synthesis of 1,4-Keto-Alkenylboronate Esters and 1,4-Dicarbonyls.
Angew Chem Int Ed Engl
; 58(40): 14234-14239, 2019 10 01.
Article
em En
| MEDLINE
| ID: mdl-31353794
ABSTRACT
A catalytic enantioselective method for the synthesis of 1,4-keto-alkenylboronate esters by a rhodium-catalyzed conjugate addition pathway is disclosed. A variety of novel, bench-stable alkenyl gem-diboronate esters are synthesized. These easily accessible reagents react smoothly with a collection of cyclic α,ß-unsaturated ketones, generating a new C-C bond and stereocenter. Products are isolated in up to 99 % yield with greater than 201 E/Z and greater than 991 e.r. Mechanistic studies show the site-selectivity of transmetalation and reactivity is ligand dependent. The utility of the approach is highlighted by gram-scale synthesis of enantioenriched cyclic 1,4-diketones, and stereoselective transformations of the products by hydrogenation, allylation, and isomerization.
Palavras-chave
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Ródio
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Ácidos Borônicos
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Ésteres
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Cetonas
Idioma:
En
Revista:
Angew Chem Int Ed Engl
Ano de publicação:
2019
Tipo de documento:
Article
País de afiliação:
Estados Unidos