The reactions between triplet diphenylcarbene and fluorenylidene with a variety of sulfides and disulfides were investigated with use of electron paramagnetic resonance (EPR) spectroscopy, laser flash photolysis, and product studies. Diphenylcarbene reacted with these substrates by a radical-like displacement mechanism. Rate constants were ca. IO6 M-l s-I, and the resulting thio-substituted diphenylmethyl radicals were identified by their EPR and optical spectra. By contrast, the analogous reactions of fluorenylidene had rate constants of 108-109 M-' s-I and proceeded by an ylide mechanism. Product studies were consistent with these results but were not sufficient in themselves to reveal these mechanistic differences.
Reactions of triplet carbenes with sulfides and disulfides: Ylide vs. radical formation
Alberti A;
1986
Abstract
The reactions between triplet diphenylcarbene and fluorenylidene with a variety of sulfides and disulfides were investigated with use of electron paramagnetic resonance (EPR) spectroscopy, laser flash photolysis, and product studies. Diphenylcarbene reacted with these substrates by a radical-like displacement mechanism. Rate constants were ca. IO6 M-l s-I, and the resulting thio-substituted diphenylmethyl radicals were identified by their EPR and optical spectra. By contrast, the analogous reactions of fluorenylidene had rate constants of 108-109 M-' s-I and proceeded by an ylide mechanism. Product studies were consistent with these results but were not sufficient in themselves to reveal these mechanistic differences.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
