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Hemoproteins have recently emerged as attractive biocatalysts for catalyzing carbene-mediated cyclopropanation, a synthetically valuable reaction not found in nature. In this study, we present a hemoglobin-catalyzed strategy for the highly stereoselective synthesis of nitrile-substituted cyclopropanes. This method offers efficiency and environmental friendliness by utilizing an asymmetric olefin cyclopropanation reaction catalyzed by wild-type Vitreoscilla hemoglobin in the presence of in situ generated diazoacetonitrile. A diverse range of nitrile-substituted cyclopropanes could be synthesized in water with exceptional stereoselectivity, achieving up to 99.9% de and ee and high turnover numbers of up to 3232. By employing this sustainable approach, not only can various chiral nitrile-substituted cyclopropanes be efficiently obtained, but also the practical application of hemoglobin in organic synthesis can be expanded. [ABSTRACT FROM AUTHOR]

Organophosphorus compounds are the core structure of many active natural products. The synthesis of these compounds is generally achieved by metal catalysis requiring specifically functionalized substrates or harsh conditions. Herein, we disclose the phospha-Michael addition reaction of biphenyphosphine oxide with various substituted β-nitrostyrenes or benzylidene malononitriles. This biocatalytic strategy provides a direct route for the synthesis of C-P bonds with good functional group compatibility and simple and practical operation. Under the optimal conditions (styrene (0.5 mmol), biphenyphosphine oxide (0.5 mmol), Novozym 435 (300 U), and EtOH (1 mL)), lipase leads to the formation of organophosphorus compounds in yields up to 94% at room temperature. Furthermore, we confirm the role of the catalytic triad of lipase in this phospha-Michael addition reaction. This new biocatalytic system will have broad applications in organic synthesis. [ABSTRACT FROM AUTHOR]

In this work, an enzymatic method for the de novo construction of diverse substituted pyrazoles from readily available diazo compounds and alkynoates/allenoates in ionic liquids was established. Under the optimum reaction condition (3-alkynoates or allenoates (0.5 mmol), diazo compounds (0.6 mmol), [BMIM][PF 6 ] (2 mL), C. rugosa lipase (15 mg), 45 °C, 8 h.), pyrazoles bearing different groups were obtained in satisfactory yields (61 %−93 %). The method features a diversity of substituents of the pyrazole products and remarkably simple work-up. [Display omitted] • Enzymatic synthesis of substituted pyrazoles is reported for the first time. • A highly efficient and green biosynthesis in ionic liquid is explored. • This work extends the application of C. rugosa lipase in organic synthesis. [ABSTRACT FROM AUTHOR]

• Hemin is used as a highly efficient catalyst for the controlled synthesis of α-aminonitriles and α-iminonitriles. • High yields of the desired products were obtained with good functional group tolerance. • This work extends the application of Hemin in organic synthesis. We report an efficient and controlled oxidative cyanation approach for the synthesis of α-aminonitriles and α-iminonitriles in MeOH using Hemin (1 mol %) as a nontoxic and natural catalyst under room temperature. This work is the first report on the incorporation of a natural iron porphyrin complex as a redox catalyst for the oxidation of secondary amines. The significant features of this biomimetic strategy for the preparation of α-aminonitriles and α-iminonitriles include the use of MeOH as green and attractive solvent in an organic reaction, the use of ethyl cyanoformate as a benign cyanide source due to its mild conditions, environmentally friendly, the use of a biodegradable catalyst, no moisture sensitivity, simple workup procedure, and controllable, which all together make the current method attractive for academic research as well as industrial applications. [Display omitted] [ABSTRACT FROM AUTHOR]