4126-83-4Relevant academic research and scientific papers
Formamide Catalysis Facilitates the Transformation of Aldehydes into Geminal Dichlorides
Huy, Peter Helmut
supporting information, p. 2474 - 2483 (2019/06/08)
Herein, a novel method for the transformation of aldehydes into geminal dichlorides based on phthaloyl chloride as reagent and N -formylpyrrolidine as Lewis base catalyst is disclosed. Given the mild reaction conditions, the current protocol is distinguished by high levels of functional group compatibility and scalability and is operationally simple. The in situ formation of a Vilsmeier Haack reagent type intermediate is likely to be essential for this organocatalytic nucleophilic substitution reaction.
Halogenation through Deoxygenation of Alcohols and Aldehydes
Chen, Jia,Lin, Jin-Hong,Xiao, Ji-Chang
supporting information, p. 3061 - 3064 (2018/05/28)
An efficient reagent system, Ph3P/XCH2CH2X (X = Cl, Br, or I), was very effective for the deoxygenative halogenation (including fluorination) of alcohols (including tertiary alcohols) and aldehydes. The easily available 1,2-dihaloethanes were used as key reagents and halogen sources. The use of (EtO)3P instead of Ph3P could also realize deoxy-halogenation, allowing for a convenient purification process, as the byproduct (EtO)3Pa?O could be removed by aqueous washing. The mild reaction conditions, wide substrate scope, and wide availability of 1,2-dihaloethanes make this protocol attractive for the synthesis of halogenated compounds.
Nitrile ylide dimerization: Investigation of the carbene reactivity of nitrile ylides
Fergus, Suzanne,Eustace, Stephen J.,Hegarty, Anthony F.
, p. 4663 - 4669 (2007/10/03)
A series of novel hexaaryl diazatrienes 5 ("nitrile ylide dimers") were synthesized directly from the corresponding diaryl ketimines 12 and dichlorotoluenes 13 in a facile one-pot synthesis. The carbene character of the nitrile ylides was investigated by varying the substituents on the aromatic ring adjacent to the carbene center. The isolation of the corresponding carbene dimers as stable crystalline materials with absorption maxima (λmax) from 363 to 422 nm was shown to be promoted by the absence of strongly electron-withdrawing substituents. The crystal structures indicate that the E-isomers were isolated when phenyl, 3-methylphenyl, and 3-chlorophenyl substituents are present at the carbene carbon; the Z-isomer was isolated when the more sterically hindered 2,4,6-trimethylphenyl substituent (Mes) is present. The 1H NMR spectra of the E-isomers demonstrate the nonequivalence of the aromatic rings, in which two of the aromatic rings of the imine moiety are pseudoaxial and the remaining aromatic rings are pseudoequatorial. The reactions proceed via the intermediate nitrile ylides 1 generated by the base-promoted 1,1-elimination of HCl from the intermediate chloroimine 14. The nitrile ylide was also generated by 1,3-elimination of HCl from the imidoyl chloride 18, confirming common pathways via the nitrile ylide as the dimer products obtained from these different routes were identical. The strongly electron-withdrawing 4-nitrophenyl substituent promotes the linear carbanion character of the 1,3-dipole and no dimer is formed.
Formylation and dichloromethylation as alternative directions of rieche reaction. A novel to the synthesis of sterically hindered aromatic dialdhydes
Yakubov, Alexander P.,Tsyganov, Dmitry V.,Belen'kii, Leonid I.,Krayushkin, Mikhail M.
, p. 3397 - 3404 (2007/10/02)
A previously unknown direction of Rieche reaction has been found: formylation of mesitylene, m-xylene, and durene with dichloromethyl methyl ether in the presence of aluminium trichloride and, to lesser extent, of titanium tetrachloride give the respective benzylidene dichlorides besides aldehydes. A novel approach to the synthesis of sterically hindered aromatic dialdehydes has been offered which involves the transformation of a monoaldehyde into the corresponding benzylidene dichloride, Rieche formylation of the latter, and hydrolysis of dichloromethyl aldehyde formed.
NEW DATA ON THE FORMYLATION OF MESITYLENE AND DIMESITYLMETHANE BY DICHLOROMETHYL ETHER
Yakubov, A. P.,Tsyganov, D. V.,Belen'kii, L. I.,Krayushkin, M. M.
, p. 1707 - 1712 (2007/10/02)
During the formylation of mesitylene by the action of dichloromethyl methyl ether in the presence of aluminium chloride or titanium tetrachloride an appreciable amount of 2,4,6-trimethylbenzylidene chloride is formed.This indicates the possible appearance of the CHCl2+ cation as intermediate particle.The disubstituted products are formed in addition to the monosubstitution products.In addition to the corresponding dialdehyde, the formylation of dimesitylmethane leads to the formation of products which contain one benzene ring and appear during cleavage of thesubstrate and subsequent substitution (formylmesitylene, dichloromethylmesitylene, chloromethylmesitylenecarbaldehyde, chloromethyl-2,4,6-trimethylbenzylidene chloride).
