RESUMO
A general and efficient asymmetric synthesis of cyclic indoline aminals was developed with a high level of 1,3-stereoinduction through a dynamic crystallization-driven condensation. Dehydrogenation of the indoline aminals with potassium permanganate produced the corresponding cyclic indole aminals in high yields and excellent enantioselectivities. This general methodology was successfully applied to the synthesis of a wide variety of chiral cyclic indoline aminals and indole aminals with aromatic and aliphatic functional groups.
Assuntos
Indóis/síntese química , Catálise , Indóis/química , Estrutura Molecular , EstereoisomerismoRESUMO
Recent methods for the synthesis of aziridines and aziridinium ions, the mechanisms of their nucleophilic ring-opening reactions and applications to the practical synthesis of pharmaceutical intermediates are reviewed.
Assuntos
Aziridinas/síntese química , Aziridinas/metabolismo , Preparações Farmacêuticas/síntese química , Preparações Farmacêuticas/metabolismo , Tecnologia Farmacêutica/métodos , Animais , Humanos , ÍonsRESUMO
[reaction: see text] A new and practical method for the synthesis of 1- and 1,3-substituted xanthines is reported. Direct base-promoted condensation of the imidazole precursor 1 with carbamates 2 gives 1-substituted 7-PMB xanthines 7 in good yields. Alkylation of these derivatives or their potassium salts proceeds under mild conditions to give functionalized 1,3-substituted 7-PMB xanthines 9 in good to excellent yields. The obtained 7-PMB-protected derivatives can be readily deprotected to give the parent 1- and 1,3-substituted xanthines.
Assuntos
Xantinas/síntese química , Alquilação , Carbamatos/química , Imidazóis/químicaRESUMO
A concise, enantioselective synthesis of the HCV NS5a inhibitor MK-8742 (1) is reported. The features of the synthesis include a highly enantioselective transfer hydrogenation of an NH imine and a dynamic diastereoselective transformation. The synthesis of this complex target requires simple starting materials and nine linear steps for completion.