21752-86-3Relevant academic research and scientific papers
[2 + 2] cycloreversion of [4.3.2]propella-1,3,11-trienes: An approach to cyclo[n]carbons from propellane-annelated dehydro[n]annulenes
Tobe, Yoshito,Fujii, Toshihiko,Matsumoto, Hideki,Tsumuraya, Kunihiro,Noguchi, Daisuke,Nakagawa, Nobuko,Sonoda, Motohiro,Naemura, Koichiro,Achiba, Yohji,Wakabayashi, Tomonari
, p. 1762 - 1775 (2000)
As a method to generate all-carbon molecules having highly reactive polyyne units from stable precursors, the [2 + 2] cycloreversion of [4.3.2]propella-1,3,11-triene derivatives was developed. To test the efficiency of this method, the reaction was first applied to simple diethynyl- and dibutadiynyl-substituted propellatrienes, which produced upon UV-irradiation linear hexatriyne and decapentayne derivatives, respectively. Next, dehydro[12]-, [16]-, [18]-, [20]-, and [24]annulene derivatives annelated by the [4.3.2]propellatriene units were prepared as precursors to the corresponding cyclo[n]carbons, a monocyclic form of carbon clusters. Laser-desorption mass spectra of the dehydroannulenes exhibited, in the negative mode, peaks due to the corresponding cyclo[n]carbon anions (n = 12, 16, 18, 20, and 24) formed by successive losses of aromatic indane fragments. Solution photolysis of the dehydro[16]annulene and dehydro[18] annulene derivatives formed reactive polyyne intermediates by [2 + 2] cycloreversion which were intercepted by furan to give the corresponding Diels-Alder adducts. The structures and spectroscopic properties of the dehydroannulenes annelated by the [4.3.2]propellatriene units, the precursors to cyclo[n]carbons, and those annelated by the oxanorbornadiene units, the products of the photolysis in furan, are discussed.
Expanded Radialenes with Bicyclo[4.3.1]decatriene Units: New Precursors to Cyclo[n]carbons
Tobe, Yoshito,Umeda, Rui,Iwasa, Naruhito,Sonoda, Motohiro
, p. 5549 - 5559 (2007/10/03)
A new method for the formation of conjugated polyynes has been developed based on both the rearrangement of vinylidenes to alkynes and the [2+1] cheletropic fragmentation of dialkynylmethylenebicyclo-[4.3.1]deca-1,3,5-triene derivatives. A model study of the photolysis of simple dialkynylmethylenebicyclo[4.3.1]deca-1,3,5-trienes resulted in cheletropic fragmentation followed by 1,2-migration to give the corresponding linear polyynes, although undesired isomerization to methylenebicyclo[5.3.0]triene derivatives took place concurrently. Expanded [3]-, [4]-, [5]-, and [6] radialene derivatives with exocyclic bicyclo[4.3.1]decatriene units were prepared by oxidative coupling of the monomeric units as precursors to the corresponding cyclo[n]carbons, monocyclic forms of carbon clusters. The spectroscopic properties of the expanded radialenes were investigated in connection with cross conjugation of the core π system and with its perturbation by the extraannular bicyclic π system. In negative-mode laser-desorption time-of-flight (LD-TOF) mass spectra, the expanded radialenes exhibited peaks due to the corresponding cyclo[n]carbon anions (n = 18, 24, 30, and 36) formed by the stepwise loss of the aromatic indane fragments.
Vinylidene to alkyne rearrangement to form polyynes: Synthesis and photolysis of dialkynylmethylenebicyclo[4.3.1]deca-1,3,5-triene derivatives
Tobe, Yoshito,Iwasa, Naruhito,Umeda, Rui,Sonoda, Motohiro
, p. 5485 - 5488 (2007/10/03)
Dialkynylmethylenebicyclo[4.3.1]deca-1,3,5-triene derivatives were synthesized as precursors to generate dialkynylvinylidenes by extrusion of an aromatic fragment, indane. Photolysis of the trienes gave linear polyynes as the major products produced by rearrangement of the vinylidenes, together with the isomerization products having a methylenecycloheptatriene moiety.
Photochemical Method for Generation of Linear Polyynes: Cycloreversion of Propellatrienes Extruding Indan
Tobe, Yoshito,Fujii, Toshihiko,Naemura, Koichiro
, p. 1236 - 1237 (2007/10/02)
Photolysis of trienediynes 1a and 1b and trienetetrayne 1c having a propellane framework yielded the respective linear polyynes 2a-c in good efficiency through cycloreversion, extruding indan (3).
