24442-69-1Relevant articles and documents
Synthesis of Alkenyl- and Alkynylcyclopropenes
Haley, Michael M.,Biggs, Bluegrass,Looney, Will A.,Gilbertson, Robert D.
, p. 3457 - 3460 (1995)
Fluoride anion promoted dehalosilation of 2-(chlorocyclopropyl)trimethylsilanes in the gas-phase was used to prepare a variety of monosubstituted cyclopropenes containing additional unsaturations.The cyclopropylsilanes were constructed easily from common intermediates.
Synthesis of stanna- and germa-cycloheptatrienes
Nakadaira, Yasuhiro,Sato, Ryuji,Sakurai, Hideki
, p. 411 - 417 (1992)
The first preparations of C-unsubstituted stannacycloheptatriene and germacycloheptatriene, analogues of cycloheptatriene, are described with their spectroscopic properties.A stannacyclohexadienyl anion derived from stannacyclohexadiene by treatment with lithium di-isopropylamide was allowed to react with chlorocarbene generated from dichloromethane and n-butyllithium, and this led to the formation of the corresponding stannacycloheptatriene.The disproportionation reaction between the stannacyclohexadiene and dichlorodimethylgermane gave the corresponding germacyclohexadiene in reasonable yield.In a similar manner, the reaction of the germacyclohexadienyl anion with chlorocarbene yielded C-unsubstituted germacycloheptatriene.
2-pyridylnitrene and 3-pyridazylcarbene and their relationship via ring-expansion, ring-opening, ring-contraction, and fragmentation
Kvaskoff, David,Bednarek, Pawel,Wentrup, Curt
scheme or table, p. 1600 - 1611 (2010/05/01)
(Figure Presented) Photolysis of triazolo[1,5-b]pyridazine 8 isolated in Ar matrix generates diazomethylpyridazines 9Z and 9E and diazopentenynes 11Z and 11E as detected by IR spectroscopy. ESR spectroscopy detected the 3-pydidazylcarbene 10 as well as pent-2-en-3-yn-l-ylidene 12 formed by loss of one and two molecules of N2, respectively. Further photolysis caused rearrangement of the carbenes to 1,2-pentadien-4-yne 13 and 3- ethynylcyclopropene 14. Flash vacuum thermolysis (FVT) of 8 at 400-500 °C with Ar matrix isolation of the products yielded 13, 14, and 1,4-pentadiyne 15. At higher temperatures, glutacononitriles 27Z and 27E were formed as well together with minor amounts of 2- and 3-cyanopyrroles 28 and 29. Tetrazolo[1,5-a]pyridine/2-azidopyridine 22T/22A yields 2-pyridylnitrene 19 as well as the novel open-chain cyanodienylnitrene 23 and the ring-expanded 1,3-diazacyclohepta-l,2,4,6-tetraene 21 on short wavelength photolysis. Nitrenes 19 and 23 were detected by ESR spectroscopy, and cumulene 21 by IR and UV spectroscopy. FVT of 22T/22A also affords 2-pyridylnitrene 19 and diazacycloheptatetraene 21, as well as glutacononitriles 27Z,E and 2- and 3-cyanopyrroles 28 and 29. Photolysis of 21 above 300 nm yields the novel spiroazirene 25, identified by its matrix 1R spectrum. The reaction pathways connecting the four carbenes (10Z,E and 12Z,E) and three nitrenes (19, 23EZ, and 23ZZ) in their open-shell singlet and triplet states are elucidated with the aid of theoretical calculations at DFT, CASSCF, and CASPT2 levels. Three possible mechanisms of ring-contraction in arylnitrenes are identified: (i) via ring-opening to dienylnitrenes, (ii) concerted ring-contraction, and (iii) via spiroazirenes 25, whereby (i) is the energetically most favorable.
Photochemistry of matrix-isolated cyclopentadienylidene revisited
Maier,Endres
, p. 179 - 187 (2007/10/03)
Irradiation of diazocyclopentadiene (1) in a matrix at 10 K with the wavelength λ = 366 nm leads - as already known - to rapid loss of nitrogen and the formation of cyclopentadienylidene (T-2). Upon photoexcitation of cyclopentadienylidene (2) with light of the wavelength λ = 313 nm the (s-E)-(E)-conformer of 2-penten-4-yn-1-ylidene (T-7a) can be detected, which is effectively converted into 3-ethynylcyclopropene (6) by using light with a wavelength of λ = 436 nm. The structural elucidation of T-7a and 6 is based on the comparison of the experimental and calculated IR spectra. Irradiation of cyclopentadienylidene (2), isolated together with the eliminated nitrogen in the same matrix cage, with light of wavelengths longer than 570 nm initiates a partial back-reaction to the starting material, diazocyclopentadiene (1) by recapturing the evolved nitrogen molecule.
Reactions of Monosubstituted Acetylenic Alcohols with Allyl Halides
Veliev, M. G.,Shatirova, M. I.,Chalabiev, Ch. A.,Mamedov, I. M.,Mustafaev, A. M.
, p. 52 - 56 (2007/10/03)
Reactions of 2-propynyl alcohol and 2-methyl-3-butyn-2-ol with mono- and dihalogenated propenes yield allylacetylenic alcohols.The kinetic study showed that the reaction rate is governed by both electronic and steric effects of substituents in the allyl halides.
