The use of water solutions of industrial and designer surfactants enables performing a wide variety of chemical transformation on hydrophobic precursors. Mostly reactions are clean, fast and efficient with vast benefits for overall sustainability. The widespread adoption of such methods is somewhat hampered by a lack of generality in the case of troublesome substrates and scaling up. The common literature solution for such issues is the use of small amounts of organic solvents. We here show that the use of a mixture of L-α-lecithin and Tween 80 is a preferable solution enabling the taming of particularly troublesome reactions, where even the cosolvent approach fails. The strong reduction of all interface tensions characterizing such complex multiphase systems is key to the results achieved. The protocol, applied to Suzuki-Miyaura couplings, allows to obtain complete reactions conversion at room temperature within one hour, is general and scalable from milligrams to up to 10 grams without further adjustments. File list (2) download file view on ChemRxiv SM_with_lecithin.pdf (10.40 MiB) download file view on ChemRxiv SM_with_lecithin_SI.pdf (6.63 MiB)

The technology of organometal halide perovskites is on the verge of the lab to fab transition due to particularly high efficiencies and low cost of the raw materials employed in the active later. The hole transport layer is a key enabling component of such solar cells and at the same time the one requiring more significant synthetic efforts. Alternative materials with improved sustainability are under constant development, yet 2,2′,7,7′tetrakis(N,N-di(4-methoxyphenyl)amino)-9,9′-spirobifluorene (Spiro-OMe-TAD) still represents the standard in the field. We show that the combination of solventless approaches, chemistry on water, and micellar catalysis gives access to such critical material in a fully sustainable, scalable, and efficient way. Performances are validated in devices delivering results equal to those with standard commercial Spiro-OMeTAD but greatly reducing the overall E-factora green chemistry metric measuring the waste/purified product ratio of a synthesis, from 5299 to 555, as well as eliminating chlorinated solvents and hazardous chemicals.

The Suzuki-Miyaura cross coupling reaction of 4,7-dibromo-5,6-difluoro-2,1,3-benzothiadiazole (DBBF) with different arylboronic acids can be efficiently carried out in water and under air by means of micellar coupling. The careful tuning of reaction conditions enables preparation of symmetrically and unsymmetrically substituted derivatives. The moderate to good yields obtained, alongside with the wide variety of available substitution patterns, makes this sustainable methodology very resourceful for the preparation of building blocks for luminescent optoelectronic materials.

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Perovskite solar cells (PSCs) are experiencing tremendous interest due compatibility with solution processing on a wide range of substrates and very high efficiency. The Hole Transport Layer (HTL) plays a...