The thermal isomerisation benzoazetine - 6-methylene-2,4- cyclohexadien-1-imine: A photoelectron investigation

Aza-ortho-xylylenes in Organic Synthesis

“…[15,18Ϫ21] The calculated relative stabilities of benzoazetine (5) and aza-ortho-xylylene (9) depend on the theoretical method used. Results of semiempirical MNDO calculations predict a higher stability for benzoazetine (5) than for aza-ortho-xylylene (9), [20] but results of AM1 calculations suggest the greater stability for the latter. [18] A thorough comparison of the results of calculations, semiempirical and ab initio, obtained at various theory levels has been performed by Sander et al [18,19] Results of our ab initio calculations at the MP2 theory level suggest a higher stability for aza-ortho-xylylene (9) than for benzoazetine (5).…”

“…[19] UV photoelectron spectroscopy (UV-PES) was used for detection of aza-ortho-xylylene and benzoazetine among the products formed during FVT of 2-aminobenzyl alcohol (14), 2-aminobenzylamine (15), and 1,2,3,4-tetrahydroquinoline (18). [20] No benzoazetine was detected by UV-PES among the products formed during the thermolysis of 2,1-benzisothiazoline 2,2-dioxide. [21] Scheme 4…”

A Laser Flash Photolysis Study on 2-Azido-N,N-diethylbenzylamine − The Reactivity of Iminoquinone Methides in Solution

“…As an additional photoproduct, small amounts of 2,1-benzisoxazole (8, 1%) were detected. Steady-state photolysis of 1 in acetonitrile containing 1% acrylonitrile yielded 4% of 2-aminobenzaldehyde (6), 1% of quinoline (15), 2% of the aniline 7, and a total of 7% (1% ϩ 2% ϩ 3% ϩ 1%) of compounds with m/z ϭ 229, in addition to a total of 16% of various unidentified products. A molecular mass of 229 is to be expected for the products of trapping of iminoquinone methides or 2-(diethylaminomethyl)phenylnitrene with acrylonitrile (Scheme 4).…”

“…A number of papers have dealt with their use as reactive dienes in preparative organic chemistry. [2Ϫ7] Other work has been devoted to stabilizing these highly reactive species by complexation to transition metals, [8Ϫ11] and to elucidating their properties and reactivity by using time-resolved techniques, [12Ϫ14] photoelectron spectroscopy, [15,16] or matrix isolation spectroscopy. [17Ϫ19] Quinone methides have received attention for their role in the metabolism of a number of preservatives, [20] for their potential use as anti-cancer agents and as active component of insecticides, [21,22] and for their ability to alkylate DNA efficiently.…”

Benzazetines and their derivatives (review)

“…The reactions took place as a result of elimination of C 2 H 4 , NH 3 , and H 2 O molecules respectively. Here it was found that the benzazetine (23) is formed at 650-800°C while the product at higher temperature is 6-methylene-2,4-cyclohexadiene-1-imine (24) [24,25]. Subsequent more detailed investigations of flash-vacuum pyrolysis and low-temperature photolysis in a matrix of 2-(diazomethyl)phenylamine, 1-azido-2-methylbenzene (2-tolyl azide), o-aminobenzyl alcohol, and 2-indolinone by IR and UV spectroscopy in conjunction with ab initio quantum-chemical calculations showed that these reactions take place in a more complicated manner.…”