Asymmetrichydrogenation of 4-substituted cyclic enamido esters catalyzed by a rhodium–TangPhos complex provides an efficient method for the synthesis of chiral 4-substituted oxazolinones with excellent yields and good enantioselectivities. The products are valuable chiral building blocks and the applications as chiral auxiliaries and pharmaceuticals are well-known.
usually involves using expensive starting materials and harsh reaction conditions. Herein, a one-pot biocatalytic cascade process was developed for stereo- and regioselective aminohydroxylation of diverse alkenes by combining styrene monooxygenase and halohydrin dehalogenase, providing an approach to enantiopure oxazolidinones.
Flipping the Substrate Creates a Highly Selective Halohydrin Dehalogenase for the Synthesis of Chiral 4-Aryl-2-oxazolidinones from Readily Available Epoxides
Chiraloxazolidinones are a class of important heterocyclic compounds in pharmaceutical chemistry due to their biological activity. Halohydrin dehalogenase-catalyzed epoxide ring-opening reaction with cyanate offers an attractive approach to the synthesis of chiraloxazolidinones, but the α/β-regioselectivity and stereoselectivity are still un-addressed issues. In this study, a unique halohydrin dehalogenase
手性恶唑烷酮类化合物因其生物活性而成为药物化学中一类重要的杂环化合物。卤代醇脱卤酶催化的环氧化物与氰酸酯的开环反应为合成手性恶唑烷酮提供了一种有吸引力的方法,但 α/β-区域选择性和立体选择性仍然是未解决的问题。在这项研究中,发现一种独特的卤代醇脱卤素酶 ( Ab HheG) 对外消旋氧化苯乙烯与氰酸盐的开环具有高活性和 α/β-区域选择性,但立体选择性较差 ( E < 3)。通过重塑Ab HheG的底物结合位点,获得了具有优异 α/β-区域选择性和立体选择性的变体 Y15M/N182S。变体显示E> 200 对于 13 种测试的氧化苯乙烯中的 9 种。由于 ( R )-4-aryl-2-oxazolidinones 很容易与 ( R )-styrene oxides 分离,因此 ( R )- 和 ( S )-4-aryl-2-oxazolidinones 都可以很容易地制备。晶体学和酶-
Engineering of halohydrin dehalogenases for the regio- and stereoselective synthesis of (<i>S</i>)-4-aryl-2-oxazolidinones
with excellent regioselectivity (>99 : 1) and stereoselectivity (E > 200), producing the corresponding useful and valuable (S)-4-aryl-2-oxazolidinone and (S)-SO with 98% ee. Moreover, it accepted a wider range of styrene oxides with moderate to excellent selectivity. Analysis of the substrate binding conformations showed that the regio- and stereoselectivity improvement in IcHheG was attributed to an
卤代醇脱卤酶 (HHDH) 氰酸酯介导的环氧化物开环是合成重要光学纯 2-恶唑烷酮的一种有前途的方法。然而,天然存在的 HHDH 对于苯乙烯氧化物 (SO) 的区域选择性和立体选择性仍然不能令人满意。我们使用结构引导的半理性设计来提高来自红球菌( Ic HheG) 的 HHDH 的选择性,然后对 Y18、L103、I104 和 N196 进行位点饱和和组合诱变。双突变体 I104F/N196W 对 SO 的选择性显着提高,具有优异的区域选择性 (>99 : 1) 和立体选择性 ( E > 200),产生相应的有用且有价值的 ( S )-4-芳基-2-恶唑烷酮和 ( S ) -SO 具有 98% ee。此外,它以中等至优异的选择性接受更广泛的苯乙烯氧化物。对底物结合构象的分析表明,Ic HheG 的区域选择性和立体选择性的改善归因于单个立体异构体到环氧化物环的两个碳和氧原子的几何距离的增加。这项研究阐明了负责调节Ic