Mitsunobu Approach to the Synthesis of Optically Active α,α-Disubstituted Amino Acids
作者:Jonathan E. Green、David M. Bender、Stona Jackson、Martin J. O’Donnell、James R. McCarthy
DOI:10.1021/ol802325h
日期:2009.2.19
α-azido esters by Mitsunobureaction with HN3. Optimization of this reaction was shown to proceed at room temperature with high chemical yield using 1,1-(azodicarbonyl)dipiperidine (ADDP) and trimethylphosphine (PMe3). Complete inversion of configuration was observed at the α-carbon. Several α,α-disubstituted amino acids were synthesized in high overall chemical yield and optical purity.
having a benzene-pyridine biaryl skeleton as a carbonyl catalyst, we successfully unlock the nucleophilic reactivity of the α-amino C–H bonds of α-aminoacid esters toward alkyl halides without protection of the NH2 group, forming a wide range of chiral quaternary α-aminoacid esters in up to 99% yield and 99% ee. Like transformations in biological systems, this protocol is featured with no protecting
作者:Ouyang, Yao、Page, Claire G.、Bilodeau, Catherine、Hyster, Todd K.
DOI:10.1021/jacs.4c04661
日期:——
a-Tertiary amino acids are essential components of drugs and agrochemicals, yet traditional syntheses are step-intensive and provide access to a limited range of structures with varying levels of enantioselectivity. Here, we report the α-alkylation of unprotected alanine and glycine by pyridinium salts using pyridoxal (PLP)-dependent threonine aldolases with a Rose Bengal photoredox catalyst. The strategy
a-叔氨基酸是药物和农用化学品的重要组成部分,但传统的合成是步骤密集型的,并且提供了具有不同对映选择性水平的有限范围的结构。在这里,我们报道了使用吡哆醛 (PLP) 依赖性苏氨酸醛缩酶和 Rose Bengal 光氧化还原催化剂通过吡啶盐对未受保护的丙氨酸和甘氨酸进行α-烷基化反应。该策略在单个化学步骤中有效地制备各种 a-叔氨基酸作为单个对映异构体。紫外-可见光谱研究揭示了吡啶盐、蛋白质和光催化剂之间的三元相互作用,我们假设这是将自由基形成定位到活性位点的原因。该方法突出了将光氧化还原催化剂与酶相结合以揭示已知酶的新催化功能的机会。