108604-19-9Relevant articles and documents
Spectroscopic detection of an arylchlorocarbene-ethyl acetate carbonyl ylide and subsequent oxirane formation
Chateauneuf, John E.,Liu, Michael T. H.
, p. 6585 - 6588 (2007/10/02)
Laser flash photolysis of 3-chloro-3-(p-nitrophenyl)diazirine (1) generates the corresponding ground-state singlet carbene (λmax = 310 nm), which reacts with ethyl acetate to form a carbonyl ylide of the ester (λmax = 490 nm). The absolute rate constant for ylide formation in CH2Cl2 is k = (2.85 ± 0.17) × 106 M-1 s-1. Subsequent cyclization of the ylide to the corresponding oxirane (λmax = 350 nm) occurs with a rate constant of 1.26 × 106 s-1 (21 °C) in ethyl acetate with Arrhenius activation parameters for oxirane formation of Eact = 6.68 ± 0.19 kcal/mol and log A (s-1) = 11.08 ± 0.15. The carbonyl ylide is also intercepted with the dipdarophile, diethyl fumarate, with a rate constant of (1.04 ± 0.07) × 107 M-1 s-1. Additionally, solvent polarity effects on (p-nitrophenyl)chlorocarbene reactivity and spectroscopic evidence of oxirane formation (λmax = 350 nm) from the related acetone ylide of (p-nitrophenyl)chlorocarbene are presented.
