Diastereodivergent synthesis of 2,5-diketopiperazine derivatives of β-carboline and isoquinoline from l-amino acids
摘要:
Mild Pictet-Spengler-type condensation was applied to the synthesis of several tetrahydro-beta-carboline and tetrahydroisoquinoline derivatives. L-Amino acids were promoters of 1,4-chirality transfer with up to 100% de. The stereochemistry of the final diketopiperazines strongly depended on the structure of the L-amino acids used: acyclic amino acids gave predominantly the (R)configuration at the newly created stereogenic centre, whereas L-proline afforded the opposite configuration, as established by Xray crystallography. (C) 2005 Elsevier Ltd. All rights reserved.
Diastereodivergent synthesis of 2,5-diketopiperazine derivatives of β-carboline and isoquinoline from l-amino acids
摘要:
Mild Pictet-Spengler-type condensation was applied to the synthesis of several tetrahydro-beta-carboline and tetrahydroisoquinoline derivatives. L-Amino acids were promoters of 1,4-chirality transfer with up to 100% de. The stereochemistry of the final diketopiperazines strongly depended on the structure of the L-amino acids used: acyclic amino acids gave predominantly the (R)configuration at the newly created stereogenic centre, whereas L-proline afforded the opposite configuration, as established by Xray crystallography. (C) 2005 Elsevier Ltd. All rights reserved.
Diastereoselective synthesis of some β-carboline derivatives from l-amino acids
作者:Aleksandra Siwicka、Krystyna Wojtasiewicz、Andrzej Leniewski、Jan K. Maurin、Zbigniew Czarnocki
DOI:10.1016/s0957-4166(02)00644-4
日期:2002.10
L-Ala and L-Val were used as chiral inductors in a series of reactions in which a Pictet-Spengler cyclization, completed under mild conditions was the key step. Diketopiperazine 7a and 8a having R configuration at the newly created stereogenic center were obtained with good diastereoselectivity due to 1,4-chirality transfer. Surprisingly, L-Pro promoted the formation of the product with S configuration in the predominant diastereomers 9a and 10a. (C) 2002 Published by Elsevier Science Ltd.