14441-56-6Relevant academic research and scientific papers
Methylene C(sp3)-H β,β′-Diarylation of Cyclohexanecarbaldehydes Promoted by a Transient Directing Group and Pyridone Ligand
Bull, James A.,St John-Campbell, Sahra,White, Andrew J. P.
supporting information, (2020/03/10)
A hindered β-amino amide transient directing group effects di-trans-arylation of cyclohexanecarbaldehydes. The amide N-substituents are shown to affect yield and can enhance the rate of arylation compared with the α-amino acid. Addition of a pyridone ligand further enhanced reactivity. The reaction is successful for a range of aryl iodides, and various substituted cyclohexane carboxaldehydes, providing functionalized products from simple feedstocks. A mechanism is proposed evoking a transient enamine.
Palladium-catalyzed conjugate addition of organosiloxanes to α,β-unsaturated carbonyl compounds and nitroalkenes
Denmark, Scott E.,Amishiro, Nobuyoshi
, p. 6997 - 7003 (2007/10/03)
The addition of aryltrialkoxysilanes to α,β-unsaturated carbonyl compounds (ketones, aldehydes) and nitroalkenes in the presence of SbCl3, TBAF, AcOH, and a catalytic amount of Pd(OAc)2, in CH3CN at 60 °C, provides the corresponding conjugate addition products in moderate to good yields. The addition of equimolar amounts of SbCl3 and TBAF is necessary for this reaction to proceed smoothly. The arylpalladium complex, which is generated by the transmetalation from a putative hypercoordinate silicon compound, is considered to be the catalytically active species.
Design, synthesis, and application of a C2 symmetric chiral ligand for enantioselective conjugate addition of organolithium to α,β-unsaturated aldimine
Shindo, Mitsuru,Koga, Kenji,Tomioka, Kiyoshi
, p. 9351 - 9357 (2007/10/03)
A C2 symmetric chiral diether ligand, (1R,2R)-1,2-dimethoxy-1,2- diphenylethane, was designed and synthesized on the basis of the concept of an asymmetric oxygen atom. Mediated by the chiral diether, high enantioselectivities were achieved in conjugate addition of organolithiums to naphthaldehyde imine and cyclic and acyclic α,β-unsaturated aldimines. The absolute configuration of the product is predictable by the model.
Auxiliary-directed peroxidation of 1,4-dienes
Dussault, Patrick H.,Anderson, Todd A.,Hayden, Michael R.,Koeller, Kevin J.,Jason Niu
, p. 12381 - 12398 (2007/10/03)
The addition of singlet oxygen (1O2) to the proximal alkene of auxiliary-tethered 1,4-dienes and the addition of triplet oxygen 3O2) to the proximal position of the corresponding pentadienyl radicals both produce conjugated diene hydroperoxides in moderate to high diastereomeric excess. Negligible stereoselection is observed for additions of 1O2 to the distal alkene of Z,Z-heptadienes due to the lack of control of alkene conformation. Despite evidence for the intermediacy of highly constrained pentadienyl radicals, poor diastereoselection is also observed for distal addition of 3O2. The extent of olefin isomerization observed during radical oxygenations can be correlated with steric constraints on the intermediate pentadienyl and peroxyl radicals and may be relevant to literature reports of olefin isomerization during enzymatic oxygenations of unnatural fatty acids.
Intramolecular Free Radical Cyclisation of α-Anilino Alkenenitriles
Fang, Jim-Min,Chang, Han-Ting,Lin, Chun-Cheng
, p. 1385 - 1386 (2007/10/02)
Upon treatment with tributylstannane, 2-anilino 2-alkenenitriles having halo substituents at appropriate positions undergo radical cyclisations to give cycloalkyl α-aminonitriles in a stereoselective manner.
ASYMMETRIC SYNTHESIS OF 1,2-DISUBSTITUTED CYCLOALKANECARBOXALDEHYDES. PROCEDURES FOR THE HIGHLY STEREOSELECTIVE PREPARATION OF cis- AND trans-ISOMER
Kogen, Hiroshi,Tomioka, Kiyoshi,Hashimoto, Shun-ichi,Koga, Kenji
, p. 4005 - 4008 (2007/10/02)
Procedures for the asymmetric synthesis of 1,2-disubstituted cycloalkanecarboxaldehydes (7) having asymmetric tertiary and quaternary carbon atoms in vicinal positions from the corresponding cycloalkenecarboxaldehydes (2) in high diastereomeric and enanti
