A new access to 3,5-disubstituted piperazinones via Pd(0)-catalyzed amination
摘要:
An original synthetic route toward 3,5-disubstituted piperazinones has been developed. The method relies upon a 6-exo intramolecular process between a sulfonylated nitrogen atom of amino acid derivation and an eta(3)-allyl-palladium moiety. This cyclization process generates the two possible (cis and trans) diastereoisomers whose ratio depends on the amino acid employed. The bulkier the amino acid residue, the higher the observed cis:trans ratio. Convincing evidence for reversible intramolecular addition of the nitrogen nucleophile to the eta(3)-allyl-palladium complex is put forward. (C) 2003 Elsevier Science Ltd. All rights reserved.
A new access to 3,5-disubstituted piperazinones via Pd(0)-catalyzed amination
作者:Benoit Ferber、Sébastien Lemaire、Mary M. Mader、Guillaume Prestat、Giovanni Poli
DOI:10.1016/s0040-4039(03)00885-2
日期:2003.5
An original synthetic route toward 3,5-disubstituted piperazinones has been developed. The method relies upon a 6-exo intramolecular process between a sulfonylated nitrogen atom of amino acid derivation and an eta(3)-allyl-palladium moiety. This cyclization process generates the two possible (cis and trans) diastereoisomers whose ratio depends on the amino acid employed. The bulkier the amino acid residue, the higher the observed cis:trans ratio. Convincing evidence for reversible intramolecular addition of the nitrogen nucleophile to the eta(3)-allyl-palladium complex is put forward. (C) 2003 Elsevier Science Ltd. All rights reserved.
Concise enantioselective synthesis of non-proteinogenic α-aminoacids <i>via</i> an organocatalytic Mannich-type reaction
作者:Ruslan A. Kovalevsky、Alexander S. Kucherenko、Sergei G. Zlotin
DOI:10.1039/d2cc04909k
日期:——
amine-squaramide-catalyzed enantioselective Mannich-type addition of available allomaltol to N-protected aldimines was developed. The resulted adducts were readily transformed into non-proteinogenic α-amino acids and their derivatives were not easily accessible by other methods via oxidative fragmentation, esterification, amidation and deprotection reactions. The absolute (S)-configuration of the thus
开发了一种双功能叔胺-squaramide 催化的对映选择性曼尼希型加成,将可用的异麦芽酚添加到N-保护的醛亚胺。所得的加合物很容易转化为非蛋白原性 α-氨基酸,并且它们的衍生物不易通过其他方法通过氧化断裂、酯化、酰胺化和脱保护反应获得。通过将N -Ts-PheGly 旋光符号与报告数据进行比较,确定了由此获得的 α-氨基酸的绝对 ( S )-构型。