Development of a [3+3] Cycloaddition Strategy toward Functionalized Piperidines
摘要:
This paper describes a novel route to functionalized piperidines via a formal [3+3] cycloaddition reaction of activated aziridines and palladium-trimethylenemethane (Pd-TMM) complexes. The cycloaddition reaction generally proceeds enantiospecifically with ring opening at the least hindered site of the aziridine. Therefore, readily available enantiomerically pure 2-substituted aziridines can be utilized to prepare enantiomerically pure 2-substituted piperidines in good to excellent yield. The N-substituent on the aziridine proved to be crucial to the success of this reaction with only 4-toluenesulfonyl (Ts) and 4-methoxybenzenesulfonyl (PMBS) aziridines permitting smooth cycloaddition to take place. Additionally, spirocyclic aziridines have been found to participate in the [3+3] cycloaddition reaction, whereas 2,3-disubstituted aziridines can be applied to provide fused bicyclic piperidines, albeit in low yield.
Synthesis of Functionalised Piperidines Through a [3 + 3] Cycloaddition Strategy
作者:Simon J. Hedley、Wesley J. Moran、Alexander H. G. P. Prenzel、David A. Price、Joseph P. A. Harrity
DOI:10.1055/s-2001-17443
日期:——
A novel approach to functionalised piperidines is described through a [3 + 3] cycloaddition reaction of aziridines with Pd-trimethylenemethane complexes. Importantly, the employment of enantiomerically pure aziridines (prepared in three steps from the appropriate amino acids) allows the corresponding piperidines to be furnished in enantiomerically pure form. Additionally, the application of this technique in the total synthesis of (-)-pseudoconhydrine is described.
Development of a [3+3] Cycloaddition Strategy toward Functionalized Piperidines
作者:Simon J. Hedley、Wesley J. Moran、David A. Price、Joseph P. A. Harrity
DOI:10.1021/jo030002c
日期:2003.5.1
This paper describes a novel route to functionalized piperidines via a formal [3+3] cycloaddition reaction of activated aziridines and palladium-trimethylenemethane (Pd-TMM) complexes. The cycloaddition reaction generally proceeds enantiospecifically with ring opening at the least hindered site of the aziridine. Therefore, readily available enantiomerically pure 2-substituted aziridines can be utilized to prepare enantiomerically pure 2-substituted piperidines in good to excellent yield. The N-substituent on the aziridine proved to be crucial to the success of this reaction with only 4-toluenesulfonyl (Ts) and 4-methoxybenzenesulfonyl (PMBS) aziridines permitting smooth cycloaddition to take place. Additionally, spirocyclic aziridines have been found to participate in the [3+3] cycloaddition reaction, whereas 2,3-disubstituted aziridines can be applied to provide fused bicyclic piperidines, albeit in low yield.