Synthesis of bicyclic 2,6-diketopiperazines via a three-step sequence involving an Ugi five-center, four-component reaction
摘要:
A three-step sequence involving an Ugi five-center, four-component reaction (U-5C-4CR), amide N-detertbutylation and cyclocondensation has been developed for easy access to diverse bicyclic 2,6-diketopiperazine (2,6-DKP) derivatives. In the key step, aromatic aldehydes were successfully coupled with cyclic alpha-amino acids and isocyanides in the course of U-5C-4CR. Boron trifluoride-acetic acid complex was developed as a new N-detertbutylating agent effective at rt. (C) 2012 Elsevier Ltd. All rights reserved.
Synthesis of bicyclic 2,6-diketopiperazines via a three-step sequence involving an Ugi five-center, four-component reaction
摘要:
A three-step sequence involving an Ugi five-center, four-component reaction (U-5C-4CR), amide N-detertbutylation and cyclocondensation has been developed for easy access to diverse bicyclic 2,6-diketopiperazine (2,6-DKP) derivatives. In the key step, aromatic aldehydes were successfully coupled with cyclic alpha-amino acids and isocyanides in the course of U-5C-4CR. Boron trifluoride-acetic acid complex was developed as a new N-detertbutylating agent effective at rt. (C) 2012 Elsevier Ltd. All rights reserved.
A series of novel stereochemically pure derivatives of the investigative broad-spectrum anticonvulsant ADD408003 was designed and synthesized. Five-center four-component (U-5C-4CR) and four-center three-component (U-4C-3CR) variants of Ugi reaction were used in the key step of the synthetic pathways. The compounds obtained were evaluated for the anticonvulsant activitiy in the maximal electroshock seizure (MES), subcutaneous Metrazole (scMET) and minimal clonic seizure (6 Hz) animal models of epilepsy. The efficacies of most derivatives in the 6 Hz model of pharmacoresistant partial seizures were markedly higher than in the ‘classical’ MES and scMET models. The most active compounds, (4R,8aR)-3a, and (4S,8aS)-6 displayed median effective doses (ED50) of 47.90 and 126.19 mg/kg, respectively, for the 6 Hz test.
The synthesis of a series of new chiral α-aminonitriles was achieved in a diastereoselective Strecker reaction in a one-pot procedure with aldehydes, enantiopure amines, and acetone cyanohydrin in water. Primary and secondary amines derived from L-α-amino acids were used as sources of chirality. The reactions proceeded efficiently without any catalyst at room temperature. The diastereoselectivity of
A three-step sequence involving an Ugi five-center, four-component reaction (U-5C-4CR), amide N-detertbutylation and cyclocondensation has been developed for easy access to diverse bicyclic 2,6-diketopiperazine (2,6-DKP) derivatives. In the key step, aromatic aldehydes were successfully coupled with cyclic alpha-amino acids and isocyanides in the course of U-5C-4CR. Boron trifluoride-acetic acid complex was developed as a new N-detertbutylating agent effective at rt. (C) 2012 Elsevier Ltd. All rights reserved.