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Here we describe the development of biaryl 2,5‐diphenylphospholanes as a new class of C2‐symmetric, monodentate ligands for asymmetric Suzuki‐Miyaura (ASM) reactions. Screening of a series of exemplary phospholanes led to the identification of two ligands that were used to prepare a range of atropisomeric biaryl and heterobiaryl products with good to excellent levels of enantioselectivity (up to 97:3 e.r.) under mild conditions. DFT studies suggest that the formation of a constraining ligand pocket and coordination of one of the biaryl methoxy groups in the optimised ligands to the metal centre is crucial for restricting conformational freedom in the bond‐forming step. [ABSTRACT FROM AUTHOR]

High throughput experimentation (HTE) has enabled the rapid identification of ligand/precatalyst combinations that facilitate highly enantioselective hydrogenations of prochiral N‐alkyl α‐aryl ketimines containing a furyl moiety. The chiral amines obtained have proven to be modular precursors in the synthesis of unnatural mono N‐alkylated arylalanines and related derivatives. [ABSTRACT FROM AUTHOR]

A continuous‐flow protocol utilizing syngas (CO and H2) was developed for the palladium‐catalyzed reductive carbonylation of (hetero)aryl bromides to their corresponding (hetero)aryl aldehydes. The optimization of temperature, pressure, catalyst and ligand loading, and residence time resulted in process‐intensified flow conditions for the transformation. In addition, a key benefit of investigating the reaction in flow is the ability to precisely control the CO‐to‐H2 stoichiometric ratio, which was identified as having a critical influence on yield. The protocol proceeds with low catalyst and ligand loadings: palladium acetate (1 mol % or below) and cataCXium A (3 mol % or below). A variety of (hetero)aryl bromides at a 3 mmol scale were converted to their corresponding (hetero)aryl aldehydes at 12 bar pressure (CO/H2=1:3) and 120 °C reaction temperature within 45 min residence time to afford products mostly in good‐to‐excellent yields (17 examples). In particular, a successful scale‐up was achieved over 415 min operation time for the reductive carbonylation of 2‐bromo‐6‐methoxynaphthalene to synthesize 3.8 g of 6‐methoxy‐2‐naphthaldehyde in 85 % isolated yield. Studies were conducted to understand catalyst decomposition within the reactor by using inductively coupled plasma–mass spectrometry (ICP–MS) analysis. The palladium could easily be recovered using an aqueous nitric acid wash post reaction. Mechanistic aspects and the scope of the transformation are discussed. Achieving the 'flow': The development of a continuous‐flow protocol for a Pd‐catalyzed formylation of (hetero)aryl bromides using carbon monoxide and hydrogen is described. The applicability of the continuous‐flow protocol is demonstrated on several (hetero)aryl bromide substrates. The intensified continuous‐flow process enables safe and scalable Pd‐catalyzed formylation using gases. [ABSTRACT FROM AUTHOR]

A continuous-flow protocol for Pd-catalyzed olefin cleavage by using molecular oxygen as the sole oxidant to give carbonyl compounds was explored. The developed flow protocol allowed the use of a low catalyst loading (0.1 mol %), and decomposition of the active catalyst was prevented through stabilization by poly(ethylene glycol)-400 (PEG-400), which was present as a cosolvent. Radical scavengers inhibited the reaction, which indicated the involvement of a free-radical path in the reaction mechanism. The applicability of the continuous-flow protocol was demonstrated on several olefin substrates. The continuous-flow process enabled safe and scalable olefin cleavage. [ABSTRACT FROM AUTHOR]

The use of picolinic acid amide derivatives as an effective family of bidentate ligands for copper-catalysed aryl ether synthesis is reported. A fluorine-substituted ligand gave good results in the synthesis of a wide range of aryl ethers. Even bulky phenols, known to be very challenging substrates, were shown to react with aryl iodides with excellent yields using these ligands. At the end of the reaction, the first examples of end-of-life Cu species were isolated and identified as CuII complexes with several of the anionic ligands tested. A preliminary mechanistic investigation is reported that suggests that the substituents on the ligands might have a crucial role in determining the redox properties of the metal centre and, consequently, its efficacy in the coupling process. An understanding of these effects is important for the development of new efficient and tunable ligands for copper-based chemistry. [ABSTRACT FROM AUTHOR]

Aryl ethers are prepared by cross-coupling of phenols with aryl iodides in isopropyl acetate as solvent. [ABSTRACT FROM AUTHOR]

The article presents chemical equations related to the article "Picolinamides as Effective Ligands for Copper-Catalyzed Aryl Ether Formation: Structure-Activity Relationships, Substrate Scope and Mechanistic Investigations" by C. Sambiagio and others, in the "Chemistry: A European Journal" in 2014.

OAD is found to be the most efficient ligand for the process. [ABSTRACT FROM AUTHOR]