Nonracemic 3 degrees-carbamines from the asymmetric allylboration of N-trimethylsilyl ketimines with B-allyl-10-phenyl-9-borabicyclo[3.3.2]decanes.
J Am Chem Soc
; 128(27): 8712-3, 2006 Jul 12.
Article
em En
| MEDLINE
| ID: mdl-16819848
The simple and efficient asymmetric synthesis of 3 degrees -carbamines 7 from N-TMS enamines (3) and either enantiomeric form of beta-allyl-10-(phenyl)-9-borabicyclo[3.3.2]decane (1) is reported. The high reactivity (<1 h, -78 degrees C) and enantioselectivity (60-98% ee) of these substrates can be attributed to the fact that the complexation of 3 with 1 facilitates its isomerization to the corresponding syn-N-TMS ketimine complex from which allylation can occur. In addition to providing the homoallylic amines 7 with predictable stereochemistry, the procedure also permits the efficient recovery of the chiral boron moiety (50-65%) as air-stable crystalline pseudoephedrine complexes 8, which are directly converted back to 1 with allylmagnesium bromide in ether (98%).
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Compostos de Boro
/
Compostos de Organossilício
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Compostos Bicíclicos Heterocíclicos com Pontes
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Compostos Alílicos
/
Aminas
/
Iminas
Idioma:
En
Revista:
J Am Chem Soc
Ano de publicação:
2006
Tipo de documento:
Article
País de afiliação:
Porto Rico
País de publicação:
Estados Unidos