Ken-ichi Yatsugi

Oxygen-18 scrambling studies in the solvolysis of benzyl tosylates

The ion-pair return process during the solvolysis of benzyl tosylates was studied in typical solvents by means of the sulfonate18O-scrambling experiments using carbon-13 NMR spectroscopy. The substituent and solvent dependency of amount of ion-pair return in this borderline solvolysis was discussed.

Oxygen-18 scrambling studies in the solvolysis of α-(t-butyl)benzyl tosylates

Abstract The sulfonate 18 O-scrambling during the solvolysis of α-(t-butyl)benzyl tosylates was investigated in typical solvents by 13 C-NMR spectroscopy using 18 O/ 16 O isotope shift on the alkoxy 13 C-NMR signals. The existence of extensive ion-pair return comparable to product formation was explored in this k c solvolysis.

Kinetic effects of thiourea addition on benzylic solvolyses

Effects of thiourea addition on the solvolysis of benzyl, α-methylbenzyl, and α-t-butylbenzyl chlorides were investigated in 50 % aqueous acetone at 45 °C. Logarithmic plots between the second-order rate with thiourea (kN) and the corresponding solvolysis rate (ksolv) provide a scattered pattern of deviations from a straight line defined for the kc mechanism. Mechanistic change in three solvolyses was discussed based on characteristic deviation behaviors.