A Base-Promoted Reductive Coupling Platform for the Divergent Defluorofunctionalization of Trifluoromethylarenes.

We report a trifluoromethylarene reductive coupling method that dramatically expands the scope of difluorobenzylic substructures accessible via C-F bond functionalization. Catalytic quantities of a Lewis base, combined with a disilane reagent in formamide solvent, promotes the replacement of a single trifluoromethyl fluorine atom with a silylated hemiaminal functional group. The reaction proceeds through a difluorobenzyl silane intermediate that can also be isolated. Together, these defluorinated products are shown to provide rapid access to over 20 unique difluoroalkylarene scaffolds.

Organic Superbases in Recent Synthetic Methodology Research.

Organic superbases are a distinct and increasingly utilized class of Brønsted base that possess properties complementary to common inorganic bases. This Concept article discusses recent applications of commercial organic superbases in modern synthetic methodologies. Examples of the advantages of organic superbases in three areas are highlighted, including the discovery of new base-catalyzed reactions, the optimization of reactions that require stoichiometric Brønsted base, and in high-throughput experimentation technology.

Phosphine-Directed sp3 C-H, C-O, and C-N Borylation.

Benzylic C-H borylation reactions are limited, requiring new approaches to exploit their reactivity for efficient selective functionalization. The recent development of phosphine-directed C-H borylation of arenes has now been extended to benzylic substrates, providing high yield of the mono- and geminal bis-borylation products. Attempts to borylate the C-H bond α to a benzylic ether or amine resulted in C-O and C-N borylation, followed by C-H borylation to provide geminal bis-borylated products.

Accessing Ambiphilic Phosphine Boronates through C-H Borylation by an Unforeseen Cationic Iridium Complex.

Ambiphilic molecules, which contain a Lewis base and Lewis acid, are of great interest based on their unique ability to activate small molecules. Phosphine boronates are one class of these substrates that have interesting catalytic activity. Direct access to these phosphine boronates is described through the iridium-catalyzed C-H borylation of phosphines. An unconventional cationic iridium catalyst was identified as optimal for a range of phosphines, providing good yields and selectivity across a diverse class of phosphine boronates (isolated as the borane-protected phosphine). A complimentary catalyst system (quinoline-based silane ligand with [(COD)IrOMe]2 ) was optimal for biphenyl-based phosphines. Selective polyborylation was also shown providing bis- and tris-borylated phosphines. Deprotection of the phosphine boronate provided free ambiphilic phosphine boronates, which do not have detectable interactions between the phosphorus and boron atoms in solution or the solid state.

Long-term care of the tracheostomy patient.

Care of the long-term tracheostomy patient is changing. By moving the initiation of tracheostomy out of the operating room and shifting responsibility for the procedure to the medical specialist, more patients are undergoing tracheostomy for a wider spectrum of diagnoses. With much of the aftercare now directed by the medical specialist, successful reintegration of the long-term tracheostomy patient into a productive life is dependent upon the collaborative care of several disciplines directed by the specialist. To effectively care for these challenging patients, it is critical for the physician who performs tracheostomy to be aware of the new caregiving role that is now theirs.