87282-19-7Relevant academic research and scientific papers
Singlet Halophenylcarbenes as Strong Hydrogen-Bond Acceptors
Richter, Geneviève,Mendez-Vega, Enrique,Sander, Wolfram
, p. 3524 - 3532 (2016/07/06)
Chlorophenylcarbene and fluorophenylcarbene were generated in water-doped argon matrices at cryogenic temperatures by photolysis of the corresponding matrix-isolated diazirines. When diffusion of H2O in solid argon was induced by annealing of the matrices at temperatures above 20 K, hydrogen-bonded complexes between the carbenes and water were formed. UV photolysis of these complexes resulted in the formation of benzaldehyde and hydrogen halides HX. The same products were obtained after photolysis of the diazirines in amorphous water ice. Obviously, the primary insertion product of the carbenes into H-OH is unstable under these conditions, and benzaldehyde is formed via secondary photolysis. The stable primary photochemical insertion product of chlorophenylcarbene into an O-H bond was observed in the reaction of the carbene with methanol.
1,2,4,6-CYCLOHEPTATETRAENE: THE KEY INTERMEDIATE IN ARYLCARBENE INTERCONVERSIONS AND RELATED C7H6 REARRANGEMENTS
McMahon, Robert J.,Abelt, Christopher J.,Chapman, Orville L.,Johnson, Jeffery W.,Kreil, Curits L.,et al.
, p. 2456 - 2469 (2007/10/02)
Thermolysis or photolysis of phenyldiazomethane (2) produces phenylmethylene (3), which ring-expands to give 1,2,4,6-cycloheptatetraene (6).Spectroscopic and chemical evidence rule out bicyclo(4.1.0)hepta-2,4,6-triene (4), cycloheptatrienylidene (5), and bicyclo(3.2.0)hepta-1,3,6-triene (11) intermediates.The strained allene in cycloheptatetraene (6) exhibits infrared absorption at 1824 and 1816 cm-1.Deuterium substitution produces the expected 10-cm-1 shift in the allene absorption.Fluorine or chlorine substitution substantially enhances the allene absorption intensity.Deuterium labeling studies reveal that the intramolecular chemistry of cycloheptatetraene (6) involves reversible thermal or photochemical equilibriation with phenylmethylene (3).The intermolecular chemistry of 6 involves dimerization.At temperatures as low as 10 K, 6 forms a labile (2+2) dimer,7, which undergoes thermally allowed, electrocyclic ring opening to give heptafulvalene (8) upon warming to room temperature.The rearrangements of 7-acetoxynorbornadiene (9), 2-diazobicyclo(3.2.0)hepta-3,6-diene (31), and 8-diazobicyclo(2.2.2)octa-2,5-dien-7-one (33) all involve cycloheptatetraene (6) intermediates.
AZIDE AND FLUORIDE EXCHANGE REACTIONS OF HALODIAZIRINES
Moss, Robert A.,Terpinski, Jacek,Cox, D. Phillip,Denneey, Dorothy Z.,Krogh-Jespersen, Karsten
, p. 2743 - 2748 (2007/10/02)
Reactions of 3-aryl-3-bromodiazirines (11) with molten tetrabutylammonium fluoride at 25degC provide 65-74percent isolated vields of the novel corresponding 3-aryl-3-fluorodiazirines (12) Related reactions of 11 with tetrabutylammonium azide afford high yields of aryl nitriles.The latter reactions are believed to proceed through unstable intermediate 3-aryl-3-azidodiazirines (7).These reactions involve rate-determining formation of 7 and display kinetics which are first order in azide ion and bromodiazirine.The likely intermediacy of aryldiazirinium bromide ion pair between 11 and 7 is supported by a combination of salt effect, leaving group effect and Hammett studies.Molecular orbital calculations are employed to characterize azidodiazirines as well as the mode of their decomposition to nitriles.In particular, we consider the possible itermediacy of a 3-nitrenodiazirine or an azidocarbene.
ABSOLUTE RATE CONSTANTS FOR THE ADDITIONS OF HALOPHENYLCARBENES TO ALKENES; A REACTIVITY-SELECTIVITY RELATION
Cox, D. Phillip,Gould, Ian R.,Hacker, Nigel P.,Moss, Robert A.,Turro, Nicholas J.
, p. 5313 - 5316 (2007/10/02)
The absolute rate constants determined for the additions of FCPh, ClCPh, and BrCPh to Me2C=CMe2, Me2C=CHMe, trans-MeCH=CHEt, and n-BuCH=CH2, appear to follow a reactivity/selectivity pattern of the "normal" (inverse) type.
