Takekuma SI, Sonoda K, Minematsu T, Takekuma H. An efficient preparation and spectroscopic and electrochemical properties of quinodimethane derivatives with four 3-(methoxycarbonyl)azulen-1-yl groups. Tetrahedron 2008. [DOI: 10.1016/j.tet.2008.02.012] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]

Takekuma SI, Tamura M, Minematsu T, Takekuma H. An efficient preparation, crystal structures, and properties of monocarbenium-ion compounds stabilized by 3-guaiazulenyl and anisyl groups. Tetrahedron 2007. [DOI: 10.1016/j.tet.2007.09.001] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]

Reactions of azulene and guaiazulene with all-trans-retinal and trans-cinnamaldehyde: comparative studies on spectroscopic, chemical, and electrochemical properties of monocarbenium-ions stabilized by expanded π-electron systems with an azulenyl or 3-guaiazulenyl group. Tetrahedron 2007. [DOI: 10.1016/j.tet.2007.02.071] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]

Reactions of guaiazulene with thiophene-2,5-dicarbaldehyde and furan-2,5-dicarbaldehyde in methanol in the presence of hexafluorophosphoric acid: a facile preparation and properties of delocalized dicarbenium-ion compounds stabilized by two 3-guaiazulenyl groups and a thiophene (or furan) ring. Tetrahedron 2007. [DOI: 10.1016/j.tet.2006.12.093] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]

Takekuma SI, Sonoda K, Fukuhara C, Minematsu T. Reaction of guaiazulene with o-formylbenzoic acid in diethyl ether (or methanol) in the presence of hexafluorophosphoric acid: comparative studies on 1H and 13C NMR spectral properties of 3-guaiazulenylmethylium- and 3-guaiazulenium-ion structures. Tetrahedron 2007. [DOI: 10.1016/j.tet.2006.12.094] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]

Ito S, Kawakami J, Tajiri A, Ryuzaki D, Morita N, Asao T, Watanabe M, Harada N. Synthesis and Dynamic Stereochemistry of Azulene-Substituted 9-Fluorenyl, 9,10-Dihydro-10,10-dimethyl-9-anthryl, 10,11-Dihydro-5H-dibenzo[a,d]cyclohepten-5-yl, and 5H-Dibenzo[a,d]cyclohepten-5-yl Cations. Correlations of Stabilities of the Carbocations and Rotational Barrier of Azulene Ring. BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 2005. [DOI: 10.1246/bcsj.78.2051] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]