Fig. 5: Mechanistic study.
From: Photo-induced ring-maintaining hydrosilylation of unactivated alkenes with hydrosilacyclobutanes
a Control experiments: non-strained cyclic and acyclic silanes under the standard conditions. “c.”: conversion; “y.”: yield. b Control experiment without i-Pr3SiSH. c Radical clock experiment. d EPR study of 1a. e The bond dissociation energies (ΔH) of Si/S–H bonds. f Proposed mechanism. The strained silyl radicals could be generated by direct irradiation and added to the alkene; the presence of the catalytic amount of i-Pr3SiSH could accelerate the reaction through polarity-matched hydrogen atom transfer. Calculations were performed at the M06-2X/6-311G (d, p)/SMD (THF) level of theory with (data shown outside the parentheses) and without (data shown inside the parentheses) explicit THF. “TS”: transition state.
