Reactions and diastereoselectivity of N2-arylsulfonyl amidine anions
摘要:
Cyclic N1-alkyl-N2-sulfonyl amidine anions undergo stereoselective aldol reactions to give the syn diastereoisomer as the major product. The ratio of syn to anti aldol products decreases as the size of the N1-alkyl increases. This is interpreted as a change in the transition state from an open-aldol to a closed-Zimmerman-Traxler-type transition state.
In the presence of aldehyde, a facile method was developed to obtain N-sulfonyl amidines under metal- and oxidant-free conditions by the decarboxylative of proline. This transformation features a double C–N bond formation and allows for the green synthesis of the N-sulfonyl amidines on the basis of mild conditions.
Synthesis of N-sulfonylamidines via three-component reaction of proline, aldehydes, and sulfonyl azides under metal-free conditions
作者:Fattaneh Mohammadpour、Arash Ghaderi
DOI:10.1007/s00706-022-02914-y
日期:2022.6
Synthesis of N-sulfonylamidines was performed by three-component couplingreaction of proline, aldehydes, and sulfonyl azides under mild conditions. In this reaction, using acetophenone as a representative ketone instead of aldehydes gave the desired product albeit in low yield. During our mechanistic studies, we trapped the nitrene as the key intermediate using PPh3. This simple and practical approach