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Anhydrous tert-butyl hydroperoxide (TBHP) is a powerful oxidizing agent in many chemical transformations. Despite the versatility in organic reactions, the use of anhydrous TBHP has been greatly limited because of safety concerns over its shipping, handling, and storage, particularly on production scale. Herein we describe a membrane pervaporation method that allows the production of the anhydrous TBHP solution in continuous manner. The system consists of membrane modules in series that are made of perfluorinated polymer with very high gas permeability, allowing it to remove water efficiently. The pervaporation skid has been successfully implemented in production by continuously generating anhydrous 1.5 M TBHP solution in nonane at a rate of up to 100 mL·min–1 for more than 96 h, achieving the target of 0.15 wt % water. An integrated flow oxidation of a γ-butyrolactam substrate provides an efficient and diastereoselective synthesis of a key lactam intermediate for the preparation of a drug candidate targeting interleukin-1 receptor associated kinase 4 for the treatment of inflammation and oncology diseases.

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The synthesis of proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitor 3 is described. This complex structure contains a tetrazole modified by a chiral hemiaminal carbonate prodrug. A regioselective tin-mediated alkylation was utilized to access the N-1 alkylated tetrazole isomer, and a highly selective enzymatic hydrolysis efficiently provided the desired prodrug enantiomer. A Suzuki–Miyaura coupling was employed for the final fragment union, which was challenging due to base sensitivity of the prodrug. This route was enabled and used to manufacture multikilogram quantities of API 3 in an efficient manner.

Enzymatic reductive amination being highly novel, selective and green methodology has attracted significant interest in a short period of time. This article describes, discovery of novel RedAm activity and enzyme engineering to improve its performance over >200-fold, to make it suitable for commercial scale manufacturing. The enzymatic process was successfully implemented on commercial scale to make multi metric ton of a key intermediate for Abrocitinib manufacturing. This is the first application of RedAm technology for commercial scale manufacturing of a secondary amine via direct reductive amination of a ketone with methyl amine. This work contributes to the rapidly developing field of enzyme catalysis that is emerging as a critical strategy as a sustainable alternative to existing methods.