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Disulfides, as fundamental scaffolds, are widely present in peptides, natural products, and pharmaceutical molecules. However, traditional synthesis of disulfides often involves the utilization of toxic reagents or environmentally unfriendly reaction conditions. In this work, a green and efficient method was developed for synthesizing pyrrole disulfides using β-ketothioamides and ethyl cyanoacetate as substrates, with lipase serving as a catalyst. Under the optimal conditions (β-Ketothioamides (1 mmol), ethyl cyanoacetate (1 mmol), PPL (200 U), and EtOH (5 mL)), lipase leads to the formation of pyrrole disulfides in yields of up to 88% at 40 °C. The related mechanism is also speculated in this paper. This approach not only presents a new application of lipase in enzyme catalytic promiscuity, but also offers a significant advancement in the synthetic pathway for pyrrole disulfides and aligns with the current mainstream research direction of green chemistry, contributing to the further development of environmentally friendly biocatalytic processes. [ABSTRACT FROM AUTHOR]

A green and efficient method for the construction of functionalized 2,3-dihydrothiophene derivatives in water was reported. In this work, Novozym 435 acted as a remarkable biocatalyst in catalyzing the four-component reaction of aldehydes, malonitrile or ethyl cyanoacetate, 1,3-thiazolidinedione, and amines under mild conditions. Excellent yields (85–95%) of all the corresponding products could be obtained in reasonable reaction time. Moreover, Novozym 435 could be reused for six cycles with a yield of at least 80%. The rationality of this multicomponent reaction mechanism was also verified via control experiments. [ABSTRACT FROM AUTHOR]

As a base structural unit, 1,4-dihydropyridines (DHPs) containing benzosultams widely exist in bioactive molecules and drugs. These compounds are generally synthesized by organic-base catalyzed methods that require specifically functionalized substrates or harsh conditions. Herein, a [3+3] annulation reaction of cyclic N-sulfonyl ketimine with various substituted isatylidene malononitrile or benzylidene malononitriles was documented. This biocatalytic strategy provides a green route for synthesis of 1,4-DHPs containing benzosultams, with good functional groups compatibility and yields. Under optimal conditions, lipase leads to the formation of 1,4-DHPs containing benzosultams in up to 87% yield. [ABSTRACT FROM AUTHOR]

A metal‐free, straightforward, non‐hazardous reagent‐added, one‐pot approach for the efficient synthesis of 2‐arylimino‐2H‐chromenes with high yields was developed for the first time in this report through the coupling of salicylaldehydes with β‐ketothioamides, which was catalyzed by lipase in water. This green strategy provides an efficient method to obtain various 2‐arylimino‐2H‐chromenes and enriches the practical application of biocatalysis. [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 study, supercritical carbon dioxide (ScCO2), which is a sustainable and green solvent, was used as a reaction medium in the lipase‐catalyzed synthesis of anthrone‐functionalized benzylic amines for the first time. We synthesized the target compounds via a lipase‐catalyzed multicomponent cascade reaction of aldehydes, sulfonamides, and anthrones in ScCO2. The reaction can be accomplished in good‐to‐excellent yields (77 %–95 %) and can exhibit good functional group tolerance. In brief, the reaction was characterized by step economy, metal‐free conditions, environmentally friendly solvents, and biocatalysts. [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]