Photon Equivalents as a Parameter for Scaling Photoredox Reactions in Flow: Translation of Photocatalytic C-N Cross-Coupling from Lab Scale to Multikilogram Scale.

With the development of new photocatalytic methods over recent decades, the translation of these chemical reactions to industrial-production scales using continuous-flow reactors has become a topic of increasing interest. In this context, we describe our studies toward elucidating an empirically derived parameter for scaling photocatalytic reactions in flow. By evaluating the performance of a photocatalytic C-N cross-coupling reaction across multiple reactor sizes and geometries, it was demonstrated that expressing product yield as a function of the absorbed photon equivalents provides a predictive, empirical scaling parameter. Through the use of this scaling factor and characterization of the photonic flux within each reactor, the cross-coupling was scaled successfully from the milligram scale in batch to a multi-kilogram reaction in flow.

Aryl amination using ligand-free Ni(II) salts and photoredox catalysis.

Over the past two decades, there have been major developments in transition metal-catalyzed aminations of aryl halides to form anilines, a common structure found in drug agents, natural product isolates, and fine chemicals. Many of these approaches have enabled highly efficient and selective coupling through the design of specialized ligands, which facilitate reductive elimination from a destabilized metal center. We postulated that a general and complementary method for carbon-nitrogen bond formation could be developed through the destabilization of a metal amido complex via photoredox catalysis, thus providing an alternative approach to the use of structurally complex ligand systems. Here, we report the development of a distinct mechanistic paradigm for aryl amination using ligand-free nickel(II) salts, in which facile reductive elimination from the nickel metal center is induced via a photoredox-catalyzed electron-transfer event.

Imaging EGFR and HER2 by PET and SPECT: a review.

In an effort to discover a noninvasive method for predicting which cancer patients will benefit from therapy targeting the EGFR and HER2 proteins, a large body of the research has been conducted toward the development of PET and SPECT imaging agents, which selectively target these receptors. We provide a general overview of the advances made toward imaging EGFR and HER2, detailing the investigation of PET and SPECT imaging agents ranging in size from small molecules to monoclonal antibodies.

A synthetic method for palladium-catalyzed stannylation at the 5- and 6-benzo positions of indoles.

The stannylation of indole derivatives proceeds in good yields under palladium catalysis (5 mol %) without protection of the indolic nitrogen. The general utility of both PdCl(2)(PhCN)(2)/PCy(3) and Pd(2)dba(3)/PCy(3) as catalytic systems for the stannylation of three indole derivatives, with varying degrees of electron density, is presented.