Developing a Biocascade Process: Concurrent Ketone Reduction-Nitrile Hydrolysis of 2‑Oxocycloalkanecarbonitriles

A stereoselective bioreduction of 2-oxocycloalkanecarbonitriles was concurrently coupled to a whole cell-catalyzed nitrile hydrolysis in one-pot. The first step, mediated by ketoreductases, involved a dynamic reductive kinetic resolution, which led to 2-hydroxycycloalkanenitriles in very high enantio- and diastereomeric ratios. Then, the simultaneous exposure to nitrile hydratase and amidase from whole cells of <i>Rhodococcus rhodochrous</i> provided the corresponding 2-hydroxycycloalkanecarboxylic acids with excellent overall yield and optical purity for the all-enzymatic cascade

From oximes to tertiary alcohols in water, at room temperature and under air: a hybrid one-pot tandem assembly of enzymatic deoximation and RLi/RMgX reagents

: The highly efficient biodeoximation of aromatic ketoximes, promoted by the enzymatic oxidative system laccase/TEMPO/O2, has been successfully assembled with the fast and chemoselective addition of highly-polar s-block organometallic reagents (RLi/RMgX) en route to highly-substituted tertiary alcohols. By using this hybrid one-pot tandem protocol, tertiary alcohols have been selectively synthesized in good yields and under mild and bench-type reaction conditions (room temperature, the absence of a protecting atmosphere and aqueous media, which are non-typical conditions for polar organometallic reagents). The overall hybrid one-pot tandem transformation amalgamates two distant organic synthetic tools (RLi/RMgX reagents and enzymes) without the need for any tedious and energy/time-consuming intermediate isolation/purification steps

Stereoselective Chemoenzymatic Synthesis of Enantiopure 2‑(1<i>H</i>‑imidazol-yl)cycloalkanols under Continuous Flow Conditions

The development of continuous flow processes for the synthesis of chiral enantiopure 1-(2-hydroxycycloalkyl)­imidazoles is reported. For the ring-opening reaction microwave batch processes and continuous flow reactions have led to similar results in terms of conversion, although the productivity is clearly improved under flow. The use of continuous flow systems for the lipase-catalyzed kinetic resolution of the racemic 2-(1<i>H</i>-imidazol-yl)­cycloalkanols with either immobilized CAL-B or PSL-C has been demonstrated to be significantly more efficient than the corresponding batch processes. The continuous flow biotransformations have allowed us to easily increase the production of these chiral imidazoles, adequate building blocks in the synthesis of chiral ionic liquids

Combination of Metal-Catalyzed Cycloisomerizations and Biocatalysis in Aqueous Media: Asymmetric Construction of Chiral Alcohols, Lactones, and γ‑Hydroxy-Carbonyl Compounds

The combination of the metal-catalyzed cycloisomerization of alkynes containing a tethered nucleophile as substituent in aqueous media (followed by the spontaneous hydrolysis, hydroalkoxylation, or aminolysis of the transiently formed five-membered heterocycles) with the subsequent enantioselective ketone bioreduction (mediated by KREDs) has been achieved. The overall transformations, which formally involve a three-step one-pot reaction, provide a variety of enantiopure valuable molecules (e.g., 1,4-diols, lactones, and γ-hydroxy-carbonyl compounds (carboxylic acids, esters, and amides)) with high conversions and enantioselectivities and under mild reaction conditions, disclosing the concept of integrated metal-catalyzed cycloisomerizations of alkynes and enzymatic catalysis in water