53780-87-3Relevant articles and documents
"Cation pool" method based on C-C bond dissociation. Effective generation of monocations and dications
Okajima, Masayuki,Suga, Seiji,Itami, Kenichiro,Yoshida, Jun-Ichi
, p. 6930 - 6931 (2007/10/03)
The "cation pools" of alkoxyarylcarbenium ions were effectively generated by the oxidative C-C bond dissociation using low temperature electrolysis. The present method is especially effective for the generation and accumulation of dications, which react with carbon nucleophiles. Copyright
Preparative methodology and pyrolytic behavior of anthrylmonocarbenes: Synthesis and chemistry of 1H-cyclobuta[de]anthracene
Kendall, J. Kirby,Engler, Thomas A.,Shechter, Harold
, p. 4255 - 4266 (2007/10/03)
This study involves (1) the behavior of organolithium reagents (1-6), (2) development of efficient methods for preparing 9(7)- and 1(8)- [methoxy(trimethylsilyl)methyl]anthracenes and their analogues, (3) the intramolecular chemistry of the 9(9)- and 1(10)-anthrylcarbenes generated by pyrolyses of 7 and 8, respectively, and (4) investigation of thermal behavior and bromination of the 1H-cyclobuta[de]anthracene (11) obtained from 9 or 10. α-Methoxy-9-anthrylmethyllithium (1), prepared from 9- (methoxymethyl)anthracene (14) and t-BuLi in TMEDA/Et2O/pentane, reacts at C-10 with D2O, chlorotrimethylsilane, dimethyl sulfate, benzoyl chloride, acetaldehyde, benzaldehyde, and acetone to give, after neutralization, 9,10- dihydro-9-(methoxymethylene)-10-substituted-anthracenes 15 and 21a-f. However, lithiation of 9-(thiomethoxymethyl)anthracene (25) with t- BuLi/TMEDA/Et2O/pentane occurs by an apparent radical-anion displacement process to give 9-anthrylmethyllithium (3), which then reacts with chlorotrimethylsilane to yield 9-(trimethylsilylmethyl)anthracene (28). Similarly, 28 is formed from 25 and from 9- (trimethylsilyloxymethyl)anthracene (29) with lithium and then chlorotrimethylsilane. The electrophiles D2O, dimethyl sulfate, and benzaldehyde react with 3 at its methyl and its C-10 positions. [Methoxy(trimethylsilyl)methyl]arenes 40-42 and 7 are obtained by reactions of their aryllithium and arylmagnesium bromide precursors with bromo(methoxy)methyltrimethylsilane (39). 1-(Methoxymethyl)anthracene (45) is converted conveniently by t-BuLi and chlorotrimethylsilane to 8. Flash- vacuum pyrolyses of 7 and 8 yield 11 preparatively; 11 then thermolyzes to 2H-cyclopenta[jk]fluorene (46). Decomposition of 9-deuterio-10- [methoxy(trimethylsilyl)methyl]anthracene (55) at 650 °C/10-3 mm results in 10(56)- and 1(57)-deuteriocyclobutanthracenes, thus revealing that the 10- deuterio-9-anthrylcarbene inserts to give 56 and also isomerizes extensively before yielding 57. Of note is that 56 isomerizes thermally by C10-D movement to form 2-deuteriocyclopentafluorene 58, 57 rearranges by C10-H movement to yield deuteriocyclopentafluorene 59, and 58 and 59 equilibrate 1,5-sigmatropically. Possible mechanisms for the isomerizations of 56 and 57 are outlined. Further, bromine adds rapidly to 11 to form 9,10-dibromo-9,10- dihydro-1H-cyclobuta[de]anthracene (94), which eliminates HBr on warming to yield 10-bromo-1H-cyclobuta[de]anthracene (95).
A NEW METHOD FOR NUCLEOPHILIC OXYMETHYLATION USING α-ALKOXYSILANES. SYNTHESIS OF UNSYMMETRICAL 1,2-DIOLS
Tsuge, Otohiko,Kanemasa, Shuji,Nagahama, Hideki,Tanaka, Junji
, p. 1803 - 1806 (2007/10/02)
Desilylation of α-alkoxysilanes offers the convenient generation of carbinyl carbanions which react with a variety of carbonyl compounds giving mono-protected 1,2-diols of unsymmetrical type.Dehydration of these unsymmetrical diols leads to the regioselective formation of methyl ketones.
