β-氨基酸经常被发现是许多生物活性分子、药物和天然产物中的重要成分。特别是,由于它们提高了代谢稳定性,它们被广泛用于构建生物活性肽和肽模拟物。尽管建立了许多用于制备 β-氨基酸衍生物的方法,但这些方法中的大多数都需要金属介导的预功能化底物的多步操作。在这里,我们公开了一种无金属、能量转移的高区域选择性分子间氨基羧化反应,用于将胺和酯官能团单步安装到烯烃或(杂)芳烃中。开发了一种双功能肟草酸酯以同时产生以 C 为中心的酯和以 N 为中心的亚氨基自由基。
As part of an ongoing project concerning the synthesis of nonnatural amino acids, we have now developed a general strategy for the preparation of β2-amino acids (or 2-aminocarboxylic acid derivatives). Our procedure involves the synthesis of the sultam β-alaninate precursor 5 whose alkylation led with high yields and excellent diastereoselectivity to the precursor of β2-homophenylalanine, β2-homoalanine
Ni-catalyzed decarboxylative C(sp3)−N cross-coupling of redox active ester and oxime esters was realized through electrochemical cathodic reduction. Mechanistic studies unveil a high-valent nickel species-driven reductive elimination pathway, rather than direct radical-radical coupling. The utility of this methodology was demonstrated through a broad scope (1°, 2°, 3° carboxylic acids) and late-stage
Khlebnikov; Novikov; Nikiforova, Russian Journal of Organic Chemistry, 1999, vol. 35, # 1, p. 91 - 99
作者:Khlebnikov、Novikov、Nikiforova、Kostikov
DOI:——
日期:——
WESSJOHANN, LUDGER;MCGAFFIN, GREGORY;MEIJERE, ARMIN DE, SYNTHESIS,(1989) N, C. 359-363
作者:WESSJOHANN, LUDGER、MCGAFFIN, GREGORY、MEIJERE, ARMIN DE
DOI:——
日期:——
1,4-Addition of (Diphenylmethylene)amine to Acceptor Substituted Olefins. A Versatile Synthesis of Protected β-Amino Acids, Nitriles, and Ketones
作者:Ludger Wessjohann、Gregory Mcgaffin、Armin de Meijere
DOI:10.1055/s-1989-27252
日期:——
(Diphenylmethylene)amine [benzophenone imine, DPMA-H] cleanly reacts with a variety of α,β-unsaturated esters, nitriles, ketones, and aldehydes 1a-q to give Michael type adducts 2a-q, generally, in respectable to excellent yields. Sterically congested and donor-substituted Michael acceptors do not react. The β-amino-substituted products can be further transformed in their protected form, or selectively deprotected under mild conditions, e.g. by catalytic hydrogenation.