Nakinadines B–F: new pyridine alkaloids with a β-amino acid moiety from sponge Amphimedon sp.
摘要:
Five new 3-alkylpyridine alkaloids with a P-amino acid moiety, nakinadines B-F (1-5), have been isolated from an Okinawan marine sponge Amphimedon sp. (SS-1059), and the structures and stereochemistry were elucidated by spectroscopic data. Nakinadines B (1) and C (2) showed modest cytotoxicity. (c) 2008 Elsevier Ltd. All rights reserved.
Enantioselective Synthesis of α‐Aryl‐β
<sup>2</sup>
‐Amino‐Esters by Cooperative Isothiourea and Brønsted Acid Catalysis
作者:Feng Zhao、Chang Shu、Claire M. Young、Cameron Carpenter‐Warren、Alexandra M. Z. Slawin、Andrew D. Smith
DOI:10.1002/anie.202016220
日期:2021.5.17
The synthesis of α‐aryl‐β2‐amino esters through enantioselective aminomethylation of an arylacetic acid ester in high yields and enantioselectivity via cooperative isothiourea and Brønsted acid catalysis is demonstrated. The scope and limitations of this process are explored (25 examples, up to 94 % yield and 96:4 er), with applications to the synthesis of (S)‐Venlafaxine⋅HCl and (S)‐Nakinadine B.
证明了通过异硫脲和布朗斯台德酸协同催化,对芳基乙酸酯进行对映选择性氨甲基化,以高收率和对映选择性合成α-芳基-β 2 -氨基酯。探索了该过程的范围和局限性(25 个示例,产率高达 94% 和 96:4 er),并应用于 ( S )-文拉法辛·HCl 和 ( S )-Nakinadine B的合成。机理研究是一致的遵循 C(1)-烯醇化铵途径,而不是替代的动态动力学解析过程。对照研究表明 (i) 观察到催化剂和产物 er 之间存在线性效应;(ii)酰基铵离子可以用作预催化剂;(iii)可逆的异硫脲加成到原位生成的亚胺离子上,产生可用作生产性预催化剂的非循环中间体。
(−)-(S)-Nakinadine B: first asymmetric synthesis
作者:Stephen G. Davies、James A. Lee、Paul M. Roberts、Rushabh S. Shah、James E. Thomson
DOI:10.1039/c2cc34808j
日期:——
(â)-(S)-Nakinadine B has been synthesized for the first time (in 9 steps and 17% overall yield from commercially available atropic acid) using the conjugate addition of lithium dibenzyl-amide to an N-α-phenylacryloyl SuperQuat derivative with in situ diastereoselective enolate protonation as the key step.
Enantioselective total synthesis of (S)-nakinadine B
作者:Yuvraj Garg、Satyendra Kumar Pandey
DOI:10.1039/c6ra03915d
日期:——
A novel approach for the synthesis of α-phenyl-β2-amino acid core unit 1 and its application to the total synthesis of (S)-nakinadine B 3, a marine natural product, is described. The synthesis utilizes the optimized combination of diphenylprolinol silyl ether mediated asymmetric Michael addition and a proline catalyzed aminoxylation reactions as key steps.
Asymmetric synthesis of the marine alkaloid (−)-(S)-nakinadine C
作者:Stephen G. Davies、Paul M. Roberts、Rushabh S. Shah、James E. Thomson
DOI:10.1016/j.tetlet.2013.09.043
日期:2013.11
The first asymmetricsynthesis of the marine alkaloid (−)-(S)-nakinadine C is described. This synthesis employs the conjugate addition of lithium dibenzylamide to an N-α-phenylacryloyl SuperQuat derivative followed by diastereoselective protonation of the intermediate enolate using 2-pyridone as the key step to introduce the stereochemistry. (−)-(S)-Nakinadine C was isolated in 13% yield over 9 steps
描述了海洋生物碱(-)-(S)-那金那丁C的第一个不对称合成。该合成方法是将二苄基酰胺锂共轭添加到N -α-苯基丙烯酰基SuperQuat衍生物中,然后使用2-吡啶酮作为引入立体化学的关键步骤,对中间烯醇化物进行非对映选择性质子化。通过9步从市场上可买到的atropic酸,98:2 dr [(Z : :(E)比率]和> 99%ee的条件下,以13%的产率分离出(-)-(S)-NakinadineC 。
Nakinadines B–F: new pyridine alkaloids with a β-amino acid moiety from sponge Amphimedon sp.
Five new 3-alkylpyridine alkaloids with a P-amino acid moiety, nakinadines B-F (1-5), have been isolated from an Okinawan marine sponge Amphimedon sp. (SS-1059), and the structures and stereochemistry were elucidated by spectroscopic data. Nakinadines B (1) and C (2) showed modest cytotoxicity. (c) 2008 Elsevier Ltd. All rights reserved.