5733-76-6Relevant academic research and scientific papers
Ruthenium-catalyzed arylation of 2-alkenylpyridines with aryl bromides: Alternative E,Z-selectivity to Mizoroki-Heck reaction
Oi, Shuichi,Sakai, Kaori,Inoue, Yoshio
, p. 4009 - 4011 (2005)
(Chemical Equation Presented) Regio- and stereoselective arylation of 2-alkenylpyridines with aryl bromides is catalyzed by specific Ru(II)-phosphine complexes affording β-arylated (Z)-2-alkenylpyridines, in which the aryl moiety is introduced cis to the
Synthesis method of perhexiline drug intermediate alpha-(2,2-diphenyl vinyl) pyridine
-
Paragraph 0014; 0015, (2016/12/07)
A synthesis method of a perhexiline drug intermediate alpha-(2,2-diphenyl vinyl) pyridine includes the following steps that 1.56 mol of 1,1-diphenyl-2-(alpha-pyridyl) ethylamine, 1.8-2.1 mol of a hypochlorous phenyl ester solution and 300 ml of nitromethane are added into a reaction vessel provided with a stirrer, a reflux condenser, a thermometer and a dropping funnel, the stirring speed is controlled to be 150-190 rpm, the solution temperature is raised to 80-85 DEG C, reaction is performed for 3-5 hours, the solution temperature is reduced to 45-50 DEG C, a potassium carbonate solution is added to regulate the pH to 9-10, continuous stirring is performed for reaction for 5-7 hours, the solution temperature is reduced to 10-15 DEG C, solid precipitation, suction filtration, washing with a saline solution, washing with chlorobenzene and decoloration with a molecular sieve are performed, stirring reflux is performed for 3-4 hours, a dehydrating agent is adopted fordehydration, and recrystallization is performed in p-xylene to obtain the crystal alpha-(2,2-diphenyl vinyl) pyridine.
Single-Component Phosphinous Acid Ruthenium(II) Catalysts for Versatile C-H Activation by Metal-Ligand Cooperation
Zell, Daniel,Warratz, Svenja,Gelman, Dmitri,Garden, Simon J.,Ackermann, Lutz
supporting information, p. 1248 - 1252 (2016/01/25)
Well-defined ruthenium(II) phosphinous acid (PA) complexes enabled chemo-, site-, and diastereoselective C-H functionalization of arenes and alkenes with ample scope. The outstanding catalytic activity was reflected by catalyst loadings as low as 0.75 mol %, and the most step-economical access reported to date to angiotensin II receptor antagonist blockbuster drugs. Mechanistic studies indicated a kinetically relevant C-X cleavage by a single-electron transfer (SET)-type elementary process, and provided evidence for a PA-assisted C-H ruthenation step. A blockbuster catalyst: Well-defined ruthenium(II) phosphinous acid (PA) complexes were identified as powerful catalysts for highly selective C-H arylations with ample scope, which enabled low catalyst loadings and gave step-economical access to blockbuster drugs. Mechanistic studies were supportive of a PA-assisted C-H activation.
Iron-catalyzed stereospecific activation of olefinic C-H bonds with grignard reagent for synthesis of substituted olefins
Ilies, Laurean,Asako, Sobi,Nakamura, Eiichi
supporting information; experimental part, p. 7672 - 7675 (2011/06/26)
The reaction of an aryl Grignard reagent with a cyclic or acyclic olefin possessing a directing group such as pyridine or imine results in the stereospecific substitution of the olefinic C-H bond syn to the directing group. The reaction takes place smoothly and without isomerization of the product olefin in the presence of a mild oxidant (1,2-dichloro-2-methylpropane) and an aromatic cosolvent. Several lines of evidence suggest that the reaction proceeds via iron-catalyzed olefinic C-H bond activation rather than an oxidative Mizoroki-Heck-type reaction.
Rhodium/N-heterocyclic carbene catalyzed direct intermolecular arylation of sp2 and sp3 C-H bonds with chelation assistance
Kim, Min,Kwak, Jaesung,Chang, Sukbok
supporting information; experimental part, p. 8935 - 8939 (2010/02/28)
Rh-oadies join in: A new rhodium catalyst was developed for the chelation-assisted direct intermolecular arylation using an N-heterocyclic carbene and phosphine ligands (see scheme; IMes=1,3bis(2,4,6-trimethylphenyl) imidazol-2-ylidene). The reaction is o
Carbon-Skeletal Anionic and Radical Sigmatropic Rearrangements: Group Migratory Aptitudes as a Probe of Charge Type in the 1,2-Shifts of β-Phenyl-β-(2-pyridyl)- and β-Phenyl-β-(4-pyridyl)ethyl Systems
Eisch, John J.,Kovacs, Csaba A.,Chobe, Prabodh,Boleslawski, Marek P.
, p. 4427 - 4437 (2007/10/02)
In order to probe the occurrence and relative ease of carbon-skeletal sigmatropic rearrangements of the free-radical, anionic, or radical-anionic type, derivatives of the β,β-diphenyl-β-(2-pyridyl)- and the β,β-diphenyl-β-(4-pyridyl)ethane systems, PyPh2CCH2E (A), were treated with reagents expected to generate radical or anionic sites.The ensuing, competitive -shifts of the phenyl and/or pyridyl groups were then used as a diagnostic sign of the mechanism of rearrangement.Both the treatment of A (E = p-tolyl) with MeLi or KH and the reaction of A (E = Cl) with sodium or lithium in donor solvents caused an exclusive -pyridyl shift.Gas chromatographic and mass spectral analyses were able to place the limit of any -phenyl shift as under 0.5percent.In such alkali metal reactions, persistent aromatic radical-anions were detected by ESR spectroscopy until the completion of the reaction.Such signals and the significant amounts of carbon-carbon bond cleavage products support the formation of pyridyl radical-anions as precursors for such cleavages and -pyridyl rearrangements.That such radical-anions could lead to spiro intermediates that promote the -pyridyl migrations wins corroboration from the finding that the methiodide of 1-chloro-2-methyl-2-(4-pyridyl)propane can be reduced with lithium in THF to yield the isolable 1,1,6-trimethyl-6-azaspiroocta-4,7-diene.The same two chlorides of A responded differently under other rearrangement conditions: (1) in preparing such chlorides from the corresponding alcohols, PyPh2CCH2OH, with thionyl chloride, the 4-pyridyl isomer underwent a Wagner-Meerwein rearrangement with exclusive -phenyl migration; the 2 isomer underwent normal displacement of OH by Cl; (2) toward the free-radical reducing agent, (n-Bu)3SnH, the 2-chloro isomer underwent both -phenyl and -pyridyl shifts, while the 4-chloro isomer underwent neither reduction nor rearrangement; it simply induced the formation of hexa-n-butylditin.A similar reducing action was observed with bis(1,5-cyclooctadiene)nickel.These observations are analyzed with the aid of Hueckel molecular orbital theory and the rearrangements observed with reducing agents are assessed in terms of three types of mechanisms: (1) authentic -anionic shifts; (2) authentic -free-radical shifts; and (3) competing electron transfer from the metal to the chloride center or from the metal to the pyridyl ring, which permits anionic rearrangements to compete with rearrangements mediated by radical-anion or dianions, which latter processes form the crucial spiro intermediate by intramolecular nucleophilic displacement on the CH2Cl group.
