35699-45-7Relevant academic research and scientific papers
The influence of aromatic compound protonation on the regioselectivity of Gattermann-Koch formylation
Tanaka, Mutsuo,Fujiwara, Masahiro,Ando, Hisanori,Souma, Yoshie
, p. 159 - 160 (1996)
The regioselectivity of the Gattermann-Koch formylation is influenced by the protonation of aromatic compounds under a solvent-cage-like atmosphere.
Evidence for the intracomplex reaction in Gattermann-Koch formylation in superacids: Kinetic and regioselectivity studies
Tanaka, Mutsuo,Fujiwara, Masahiro,Xu, Qiang,Souma, Yoshie,Ando, Hisanori,Laali, Kenneth K.
, p. 5100 - 5105 (2007/10/03)
Kinetic and regioselectivity data are reported for the Gattermann-Koch formylation of m-xylene, l-methylnaphthalene, and toluene in HF-SbF5 and CF3SO3H-SbF5 as a function of SbF5/substrate molar ratio. The kinetic study for m-xylene formylation in HF-SbF5 provided crucial evidence in favor of intracomplex reaction via a third-order rate equation, [ArH][ArH2+SbF6-][CO], where the formylation electrophile HCO+ is generated by CO protonation by the arenium ion. Dependence of regioselectivity on substrate, superacid, and SbF5/substrate molar ratio showed that high para regioselectivity stems from intracomplex reaction and the observed regioselectivity reflects the ratio between the intracomplex and the conventional reactions. Comparison in regioselectivity between Gattermann-Koch formylation and Friedel-Crafts formylation with use of HCOF suggested that regioselectivity trends do not reflect the nature of the electrophile but the reaction pathway; the Friedel-Crafts formylation also appears to have intracomplex reaction character.
FORMATION OF MONOALDEHYDES BY CERIUM(IV) AMMONIUM NITRATE OXIDATION OF UNSYMMETRIC DIMETHYLNAPHTHALENES
Sydnes, Leiv K.,Hansen, Sissel H.,Burkow, Ivan C.,Saethre, Leif J.
, p. 5205 - 5208 (2007/10/02)
When 1,2-,1,3-and 1,6-dimethylnaphthalene are oxidized by Ce(4+) in acetic acid the corresponding monoaldehydes are formed in better than 80percent yield.In each case aldehyde formation takes place with a high degree of selectivity as the methyl-1-to methyl-2-naphthaldehyde ratio is better than 11:1.The selectivity may be explained from differences in reactivity as calculated within the frontier orbital method.
Ortho Metalation Directed by α-Amino Alkoxides
Comins, Daniel L.,Brown, Jack D.
, p. 1078 - 1083 (2007/10/02)
The addition of aromatic aldehydes to certain lithium dialkylamides in benzene or tetrahydrofuran gave α-amino alkoxides which were ortho lithiated with excess n-butyllithium.Subsequent alkylation and hydrolysis provided ortho-substituted aromatic aldehydes via a one-pot reaction.The ortho metalation of α-amino alkoxides derived from 1- and 2-naphthaldehyde and various substituted benzaldehydes was examined.When N,N,N'-trimethylethylenediamine was used as the amine component of the α-amino alkoxide, metalation could be carried out at lower temperatures.This rate increase is due to an intramolecular TMEDA-like assisted metalation.The synthetic utility of this ortho metalation, including how varying the amine component of the α-amino alkoxide affects the regiochemistry and metalation rate, is discussed.
A ONE-POT ORTHO ALKYLATION OF AROMATIC ALDEHYDES
Comins, Daniel L.,Brown, Jack D.,Mantlo, Nathan B.
, p. 3979 - 3982 (2007/10/02)
The addition of aromatic aldehydes to lithium N-methylpiperazide in benzene gave α-amino alkoxides which were ortho-lithiated with excess n-butyllithium.Subsequent alkylation and hydrolysis provided ortho-substituted aromatic aldehydes via a one-pot reaction.
