Benzotriazole-mediated 4-position derivatization of 2,6-diarylpyrylium cations by electrophiles
摘要:
2,6-Diaryl-4H-(benzotriazolyl)pyrans (7a-c) on treatment with n-butyllithium undergo smooth lithiation at the position a: to the benzotriazolyl moiety. In contrast to fused and bridged pyranyl derivatives, these pyranyl anions react with electrophiles by two routes: i) the expected electrophilic substitution resulting in various 4-alkyl- and 4-(omega-alkylfunctionalized)-pyrylium salts (12-19) or iii pyrylium ring rearrangement of 2,6-diarylpyrylium anions (8a-c), leading to 1,2-diaryl-3,1-cyclopentadien-1-ols (10a-c).
2,6-diphenylpyrylium and 2,6-di-t-butylpyrylium perchlorates are easily converted into a number of the corresponding 4-alkyl derivatives by photochemical reaction with tetraalkylstannanes, in MeCN at room temperature. The mechanism of the process is discussed.
BOEV V. I.; DOMBROVSKIJ A. V., ZH. OBSHCH. XIMII, 1980, 50, HO 2, 467-468
作者:BOEV V. I.、 DOMBROVSKIJ A. V.
DOI:——
日期:——
REYNOLDS, G. A.;SAEVA, F. D.;DONEY, J. J.;CHEN, CHIN, H., J. ORG. CHEM., 1984, 49, N 25, 4843-4848
作者:REYNOLDS, G. A.、SAEVA, F. D.、DONEY, J. J.、CHEN, CHIN, H.
DOI:——
日期:——
MEZHERITSKAYA L. V.; MATSKOVSKAYA E. S.; DOROFEENKO G. N., XIMIYA GETEROTSIKL. SOEDIN, 1977, HO 5, 595-598
作者:MEZHERITSKAYA L. V.、 MATSKOVSKAYA E. S.、 DOROFEENKO G. N.
DOI:——
日期:——
Redox behavior of some new bipyran and bithiopyran derivatives. One- vs. two-electron oxidations
作者:George A. Reynolds、Franklin D. Saeva、Jeffrey J. Doney、Chin H. Chen