Determination of the Concentration of Intermediaries and of Rate Constants in Radical Reactions.

Sustainable Organic Photocatalysis for Site-Selective Hydrazocoupling of Electron-Rich Arenes

“…However, the “light/dark” experiment showed that the productive reaction needs constant irradiation, which suggests the radical chain process is either not occurring or occurs for a short period. The radical chain processes have lifespans in the second or sub-second time scale, hence indicating a short-lived radical intermediate. No reaction occurred in the absence of light or PC (Table S6, Supporting Information).…”

Photocatalyzed reductive fluoroalkylation of 2-acetoxyglycals towards the stereoselective synthesis of α-1-fluoroalkyl-C-glycosyl derivatives

“…A plot of product formation versus photoreaction time revealed that during dark periods (absence of irradiation), no accumulation of product was encountered, indicating the necessity of constant illumination. 39,42 However, ordinary lifetimes for radical chain events may commonly be on the second or sub-second time scale; 43 therefore, the lack of product accumulation during dark intervals is only consistent with chains ceasing faster than the timescale of the analytical measurement employed. 44,45 The proposed mechanism is illustrated in Scheme 3.…”