Silver-catalyzed silylene transfer kinetic studies

To elucidate the mechanism of silver-catalyzed silylene transfer, kinetic studies were performed by Woerpel and coworkers (Scheme 7.17).83 The reaction of cyclohexene silacyclopropane 58 and styrene in the presence of 5mol% of (Ph3P)2AgOTf was followed using 1H NMR spectroscopy. The kinetic order in cyclohexene silacyclopropane 58 was determined to be 1. In contrast to the rate acceleration observed with increasing the concentration of 58, inhibition of the rate of the reaction was observed when styrene, cyclohexene, or triphenylphosphine concentrations were increased. Saturation kinetic behavior in catalyst concentration was observed. Activation parameters were determined to be A// = 30(1) kcal/mol and A A 31(7) eu (entropy units). Similar activation parameters were observed in... 

Scheme 7.17. Kinetic studies on silver-catalyzed silylene transfer.

Cyclohexene silacyclopropane 47 undergoes silver-catalyzed silylene transfer, acting as an efficient method for silacyclopropane 48 synthesis (Equation 5) <2004JOC4007>. Kinetic studies of the transfer reaction suggested a possible mechanism for silver-mediated silylene transfer with a kinetic order of one for 47 <2004JA9993>. 

---

See also in sourсe #XX -- [ ]

---