Photocatalytic Activity of Diverse Organic Radical Anions: Catalyst Discovery Enables Cleavage of Strong C(sp2)–N and C(sp2)–O Bonds

<div> <div> <div> <p>Herein, we leverage electrochemistry to examine the photocatalytic activity of a range of structurally diverse persistent radical anions and find that many are effective electrophotocatalysts. These studies uncover a new electron-primed photoredox catalyst capable of promoting the reductive cleavage of strong C(sp2)–N and C(sp2)–O bonds even when reduction potentials hundreds of mV more negative than Li0 are required. We illustrated several examples of the synthetic utility of these deeply reducing but otherwise safe and mild catalytic conditions. Finally, we employed electrochemical current measurements to perform a reaction progress kinetic analysis that revealed that the improved activity of this new catalyst was a consequence of an enhanced stability profile. </p> </div> </div> </div>

Photocatalytic Activity of Diverse Organic Radical Anions: Catalyst Discovery Enables Cleavage of Strong C(sp2)–N and C(sp2)–O Bonds

<div> <div> <div> <p>Herein, we leverage electrochemistry to examine the photocatalytic activity of a range of structurally diverse persistent radical anions and find that many are effective electrophotocatalysts. These studies uncover a new electron-primed photoredox catalyst capable of promoting the reductive cleavage of strong C(sp2)–N and C(sp2)–O bonds even when reduction potentials hundreds of mV more negative than Li0 are required. We illustrated several examples of the synthetic utility of these deeply reducing but otherwise safe and mild catalytic conditions. Finally, we employed electrochemical current measurements to perform a reaction progress kinetic analysis that revealed that the improved activity of this new catalyst was a consequence of an enhanced stability profile. </p> </div> </div> </div>

Synthetic and Mechanistic Studies of a Versatile Heteroaryl Thioether Directing Group for Pd(II) Catalysis

A weakly coordinating monodentate heteroaryl thioether directing group has been developed for use in Pd(II) catalysis to orchestrate key elementary steps in the catalytic cycle that require conformational flexibility in a manner that is difficult to accomplish with traditional strongly coordinating directing groups. This benzothiazole thioether, (BT)S, directing group can be used to promote oxidative Heck reactivity of internal alkenes providing a wide range of products in moderate to high yields. To demonstrate the broad applicability of this directing group, arene C–H olefination was also successfully developed. Reaction progress kinetic analysis provides insights into the role of the directing group in each reaction, which is supplemented with computational data for the oxidative Heck reaction. Furthermore, this (BT)S directing group can be transformed into a number of synthetically useful functional groups, including a sulfone for Julia olefination, allowing it to serve as a “masked olefin” directing group in synthetic planning. In order to demonstrate this synthetic utility, natural products (+)-salvianolic acid A and salvianolic acid F are formally synthesized using the (BT)S directed C–H olefination as the key step.

Synthetic and Mechanistic Studies of a Versatile Heteroaryl Thioether Directing Group for Pd(II) Catalysis

A weakly coordinating monodentate heteroaryl thioether directing group has been developed for use in Pd(II) catalysis to orchestrate key elementary steps in the catalytic cycle that require conformational flexibility in a manner that is difficult to accomplish with traditional strongly coordinating directing groups. This benzothiazole thioether, (BT)S, directing group can be used to promote oxidative Heck reactivity of internal alkenes providing a wide range of products in moderate to high yields. To demonstrate the broad applicability of this directing group, arene C–H olefination was also successfully developed. Reaction progress kinetic analysis provides insights into the role of the directing group in each reaction, which is supplemented with computational data for the oxidative Heck reaction. Furthermore, this (BT)S directing group can be transformed into a number of synthetically useful functional groups, including a sulfone for Julia olefination, allowing it to serve as a “masked olefin” directing group in synthetic planning. In order to demonstrate this synthetic utility, natural products (+)-salvianolic acid A and salvianolic acid F are formally synthesized using the (BT)S directed C–H olefination as the key step.

Single particle tracking-based reaction progress kinetic analysis reveals a series of molecular mechanisms of cetuximab-induced EGFR processes in a single living cell

Reaction progress kinetic analysis utilizing single molecule trajectories revealed the comprehensive molecular mechanisms of cetuximab induced EGFR endocytosis.