Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 4 de 4
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Org Lett ; 21(23): 9457-9462, 2019 Dec 06.
Artigo em Inglês | MEDLINE | ID: mdl-31755725

RESUMO

Pd-catalyzed regio- and enantioselective allylic etherification of vinylethylene carbonates (VECs) with diols has been developed. By using cooperative catalysts of the chiral palladium complex and triethylborane in mild conditions, the process gave monoetherified and bisetherified polyglycol derivatives with tetrasubstituted stereocenters in high yields with complete regioselectivities and high levels of enantio- and diastereoselectivities.

2.
Chem Commun (Camb) ; 55(87): 13168-13171, 2019 Oct 29.
Artigo em Inglês | MEDLINE | ID: mdl-31620731

RESUMO

An efficient method for the asymmetric synthesis of N-substituted 2-pyridones via Pd-catalyzed regio- and enantioselective allylic substitution of hydroxyl-containing allylic carbonates with 2-pyridones has been developed. By using a palladium complex in situ generated from Pd2(dba)3·CHCl3 and phosphoramidite L2 as a ligand, the process allowed rapid access to N-substituted 2-pyridones with complete chemo- and regioselectivities and good to high enantioselectivities.

3.
Org Lett ; 21(1): 214-217, 2019 01 04.
Artigo em Inglês | MEDLINE | ID: mdl-30556697

RESUMO

An efficient method for the enantioselective construction of tertiary 1,3-diols via Pd-catalyzed asymmetric allylic cycloaddition of vinyloxetanes with an abundant feedstock, formaldehyde, is developed. Using the palladium complex generated in situ from Pd2(dba)3·CHCl3 and phosphoramidite L3 as a catalyst under mild conditions, the process allows one to convert racemic 2-substituted 2-vinyloxetanes (1) to the corresponding 1,3-dioxanes (2) as methylene acetal protected tertiary 1,3-diols in high yields with good to excellent enantioselectivities.

4.
J Am Chem Soc ; 139(31): 10733-10741, 2017 08 09.
Artigo em Inglês | MEDLINE | ID: mdl-28727424

RESUMO

An efficient method for the enantioselective construction of tertiary C-O bond via asymmetric allylic substitution of racemic vinylethylene carbonates with water and alcohols has been developed. Under the cooperative catalysis system of an in situ generated chiral palladium complex and boron reagent in mild conditions, the process allowed rapid access to valuable tertiary alcohols and ethers in high yields with complete regioselectivities and high enantioselectivities. This protocol represented the first example of direct enantioselective formation of a tertiary C-O bond with water as an oxygen donor. The synthetic utilities of the process have been demonstrated by the elaboration of the products into key intermediates of biologically relevant agents, and chiral tertiary cyclic ethers could also be provided through the sequential reactions of the allylic etherification and ring-closing metathesis.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA