Cyanide abstractions from benzyl isocyanides by Tri-n-Butyltin radical: An implication of imbalanced transition state and entropy control of reactivities

Tetrahedron Letters

Volumn 38, Issue 30, 1997, Pages 5303-5306

  Kim, Sung Soo ^a   Kim, Hoon ^a   Yang, Ki Woong ^a  

^a Inha University   (South Korea)

Author keywords

[No Author keywords available]

Indexed keywords

BENZYL CYANIDE DERIVATIVE; CYANIDE; RADICAL; TRIBUTYLTIN;

ARTICLE; CHEMICAL REACTION; ENTROPY; TEMPERATURE SENSITIVITY;

EID: 0030839062     PISSN: 00404039     EISSN: None     Source Type: Journal    
DOI: 10.1016/S0040-4039(97)01185-4     Document Type: Article

References (23)

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5. 3 have been observed by esr at quite low temperatures, i.e. -20 °C. The lifetime of the intermediate radicals at 80 °C could be short enough for the steps a and b to occur almost concurrently. However the lifetime could be lengthened at the lower temperatures and the stepwise reactions could emerge.
6. The preparations of various benzyl isocyanides and the procedures of the thermal reactions at 80 °C are described in the Experimental Section of reference 2. The reactions at 0, 25, and 40 °C maintained the concentrations: a substituted benzyl isocyanide (0.5 M), benzyl isocyanide (0.5 M), tri-n-butyltin hydride (0.5 M), naphtalene(internal standard: 0.15 mM) and benzene (solvent). The tin radical has been then derived from the photolysis of tri-n-butyltin hydride at 350 nm. The photolysis was stopped at 10∼15% consumption of benzyl isocyanides. The analytical method is the same as that of the thermal reactions. The secondary α-deuterium kinetic isotope effects have been similarly obtained employing the competition method.
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