223139-72-8Relevant articles and documents
Stability and reactivity of ferrocenyl(2,4,6-trimethoxyphenyl)carbenium salts
Natsume, Satoko,Kurihara, Hideaki,Yamaguchi, Takuya,Erabi, Tatsuo,Wada, Masanori
, p. 86 - 93 (2007/10/03)
Ferrocenyl(phenyl)methanols, Fc-CHΦOH [Fc=Fe(η5-C5H5)(η5-C 5H4), Φa=2,4,6-(MeO)3C6H2 (1a); Φb=2,6-(MeO)2C6H3 (1b)], were prepared by the reactions of Fc-CHO with ΦLi. 1a reacted with only a slight excess of perchloric acid or tetrafluoroboric acid even in methanol and in 1 M HCl acid to give dark violet crystals of the carbenium salts, [Fc-CHΦa]X [X=ClO4 (2a), BF4 (2a′)]. 1b reacted with these acids in diethylether to give the carbenium salts, [Fc-CHΦb]X [X=ClO4 (2b), BF4 (2b′) (dark red-brown crystals)] in good yields. The pKR+ values could be measured in HCl acid for 1a (3.0) and for 1b (1.6). 2a and 2b were labile in hot 2-propanol to give the reduced compounds, Fc-CH2Φ. 1a and 1b reacted with 1,3,5-trimethoxybenzene, ΦaH, in 2-methyl-2-propanol containing only a slight excess of HCl acid to give diphenyl(ferrocenyl)methanes, Fc-CHΦa2 and Fc-CHΦaΦb, respectively. While 1a decomposed in neat 1,3-dimethoxybenzene, ΦbH, in the presence of acid, 1b reacted to give 2,4-dimethoxyphenyl(2,6-dimethoxyphenyl)ferrocenylmethane, Fc-CHΦbΦd [Φd=2,4-(MeO)2C6H3]. The 1H-NMR spectrum of 2a was temperature-dependent and indicated that the free rotations of both Fc and Φa groups in 2a existed at r.t. but were frozen at -60°C.
