Transition-metal complexes and purified ketoreductases work together in eutectic mixtures for the synthesis of enantiopure secondary alcohols.

Grignard and organolithium reagents undergo smooth nucleophilic additions to γ-chloroketones “on water”.

This review highlights recent advances in metal- and biocatalyzed transformations, in the synthesis of APIs and other biologically active compounds, when employing deep eutectic solvents and water as environmentally responsible solvents.

Deep eutectic solvents (DESs) are emerging as a new class of green solvents with the potential to replace organic solvents in several fundamental and applied processes. In this work, we offer an unprecedented characterization of the behavior of the bacterial photosynthetic reaction center (RC) from Rhodobacter sphaeroides in a series of choline chloride based DESs. RC is a membrane-spanning three-subunit pigment–protein complex that, upon illumination, is capable of producing a stable charge-separated state. Thus, it represents the ideal model for carrying out basic studies of protein–solvent interactions. Herein, we first report that, in many DES mixtures investigated, RC (a) is stable, (b) is capable of generating the charge-separated state, and (c) is even able to perform its natural photocycle. It proved, indeed, to be effective in reducing quinone molecules to quinol by withdrawing electrons from cytochrome c. As an example of biotechnological application, a photoelectrochemical cell based on DES-dissolved RC has also been designed and successfully employed to generate photocurrents arising from the reduction of the electron-donor ferrocenemethanol.

Transition-metal complexes and polarised organometallic reagents play together in Deep Eutectic Solvents.

Highly polarized organometallic compounds of s‐block elements are added smoothly to chiral N‐tert‐butanesulfinyl imines in the biodegradable d‐sorbitol/choline chloride eutectic mixture, thereby granting access to enantioenriched primary amines after quantitatively removing the sulfinyl group. The practicality of the method is further highlighted by proceeding at ambient temperature and under air, with very short reaction times (2 min), enabling the preparation of diastereoisomeric sulfinamides in very good yields (74–98 %) and with a broad substrate scope, and the possibility of scaling up the process. The method is demonstrated in the asymmetric syntheses of both the chiral amine side‐chain of (R,R)‐Formoterol (96 % ee) and the pharmaceutically relevant (R)‐Cinacalcet (98 % ee).

Highly polarized lithium phosphides (LiPR 2) were synthesized, for the first time, in deep eutectic solvents as sustainable reaction media, at room temperature and in the absence of protecting atmosphere, through direct deprotonation of both aliphatic and aromatic secondary phosphines (HPR 2) by n-BuLi. The subsequent addition of in-situ generated LiPR 2 to aldehydes or epoxides proceeded quickly and chemoselectively, thereby allowing the straightforward access to the corresponding αor β-hydroxy phosphine oxides, respectively, under air and at room temperature (bench conditions), which are traditionally considered as textbook-prohibited conditions in the field of polar organometallic chemistry of s-block elements.

Tea (Camellia Sinensis) is one of the most popular drink, consumed as infusion or bottled ready to drink beverages. Although tea leaves contain many antioxidants compounds, after processing they can drastically decrease, sometimes up to a full degradation, as in the case of catechin, a very healthy flavan-3-ol. In this context, the synthesis of a cocrystal between (þ)-catechin and L-(þ)-ascorbic acid, was proved to be a useful strategy to make a new ingredient able to ameliorate the antioxidant profile of both infusions and bottled teas. The obtained cocrystal showed a threefold higher solubility than (þ)catechin and its formation was elucidated unambiguously by FT-IR, thermal (DSC) and diffraction (PXRD) analyses. Antioxidant characteristics of the samples were evaluated by colorimetric assays. As expected, infusions showed much better antioxidant features than ready-to-use lemon and peach teas. The same trend was confirmed after the addition of the cocrystal at two concentration levels. In particular, supplementation at concentration of 2 mg mL À1 improved the bottled tea antioxidant values to the level showed by the not-added infusion tea.