138151-99-2Relevant academic research and scientific papers
Gold-catalyzed 1,3-transposition of ynones
Kazem Shiroodi, Roohollah,Soltani, Mohammad,Gevorgyan, Vladimir
, p. 9882 - 9885 (2014/08/05)
An efficient, regioselective gold-catalyzed 1,3-transposition reaction of ynones and diynones has been developed. It was found that stereoelectronic (interrupted conjugation) and electronic (extended conjugation) factors could efficiently govern the regio
The elusive benzocyclobutenylidene: A combined computational and experimental attempt
Nicolaides,Matsushita,Yonezawa,Sawai,Tomioka,Stracener,Hodges,McMahon
, p. 2870 - 2876 (2007/10/03)
Ab initio and density functional theory calculations predict that benzocyclobutenylidene (1) has a singlet ground state in contrast to the parent phenylcarbene and many other simply substituted arylcarbenes. Calculations also predict that 1 should lie in a relatively deep potential well, while its triplet state is 14.5 kcal mol-1 higher in energy. However, attempts to observe 1 directly by photolysis of two different nitrogenous precursors were not successful. Irradiation of diazobenzocyclobutene (7) (λ > 534 nm or λ > 300 nm) or azibenzocyclobutene (10) (λ > 328 nm) in Ar matrixes at 10 K leads to the formation of the strained cycloalkyne 7-methylenecyclohepta-3,5-dien-1-yne (3). 13C-Labeled 3 was also prepared in a similar manner. There is very good agreement between experimental IR spectra and computationally derived harmonic vibrational frequencies for 3 and [13C]-3 and excellent agreement between observed and calculated isotopic shifts. Prolonged short-wavelength irradiation converts 3 into benzocyclobutadiene (5). Phenylacetylene (6) and benzocyclobutadiene dimer (11) were identified as products arising from flash vacuum pyrolysis of diazirine 10 at 500 °C.
Molecular structure and intramolecular motion of (E)-stilbenes in crystals. An interpretation of the unusually short ethylene bond
Ogawa, Keiichiro,Sano, Takashi,Yoshimura, Shin,Takeuchi, Yoshito,Toriumi, Koshiro
, p. 1041 - 1051 (2007/10/02)
Crystal structures of (E)-2,2′-dimethylstilbene (2), (E)-2,2′4,4′-tetramethylstilbene (3), (E)-2,2′,5,5′-tetramethylstilbene (4), (E)-2,2′,4,4′,5,5′-hexamethylstilbene (5), and (E)-2,2′,3,3′-tetramethylstilbene (6) were determined at several temperatures
Thermal isomerization of benzocyclobutene
Chapman, Orville L.,Tsou, Uh-Po Eric,Johnson, Jeffery W.
, p. 553 - 559 (2007/10/02)
Thermolysis of benzocyclobutene 13CH2, 99percent gives styrene labeled in the β (48percent), ortho (30percent), α (14percent), meta (4percent), and para (4percent) positions.The major labels (β and ortho) are consistent with a mechanism involving interconversions of the isomeric tolylmethylenes and the methylcycloheptatrienes.This mechanism also involves interconversion of o-tolylmethylene with o-xylylene and p-tolylmethylene with p-xylylene.A minor mechanism produces 25percent of styrene.This mechanism involves cleavage of the aryl carbon to the methylene carbon bond in benzocyclobutene followed by hydrogen transfer to produce styrene.Thermolysis of p-xylylene produced from paracyclophane gives styrene (55percent), p-xylene (31percent), benzocyclobutene (4percent), benzene (4percent), and toluene (3percent).Thermolysis of metacyclophane gives styrene (18percent), p-xylene (25percent), m-xylene (3percent), benzocyclobutene (1percent), benzene (7percent), and toluene (22percent).
