Pannilawithana, Nuwan published the artcileExperimental and Computational Studies on the Ruthenium-Catalyzed Dehydrative C-H Coupling of Phenols with Aldehydes for the Synthesis of 2-Alkylphenol, Benzofuran and Xanthene Derivatives, Quality Control of 1205-17-0, the main research area is alkyl phenol preparation; benzofuran preparation; xanthene preparation; phenol aldehyde dehydrative coupling ruthenium catalyst.
The cationic Ru-H complex [(C6H6)(PCy3)(CO)RuH]+BF4- was found to be an effective catalyst for the dehydrative C-H coupling reaction of phenols and aldehydes to form 2-alkylphenols I [R = pentyl, Ph, 1,3-benzodioxol-5-yl, etc.; R1 = H; R2 = OMe; R3 = H; R4 = H, OMe; R1R2 = CH=CH-CH=CH; R2R3 = OCH2O]. The coupling reaction of phenols with branched aldehydes selectively formed 1,1-disubstituted benzofurans II [R5 = H; R6 = OMe; R7 = H, OMe; R8 = H, OMe; R9 = n-Pr, Et, Ph; R10 = Me, Et; R5R6 = CH=CH-CH=CH; R6R7 = OCH2O; R9R10 = (CH2)4, (CH2)5], while the coupling reaction with salicylaldehydes yielded xanthenes III [R11 = H; R12 = OMe, NEt2; R13 = H; R14 = H, OMe; R15 = H, OEt, CH=CHMe; R16 = H, OMe, Cl, F; R17 = H; R11R12 = CH=CH-CH=CH; R13R14 = CH=CH-CH=CH; R12R13 = OCH2O; R16R17 = CH=CH-CH=CH]. A normal deuterium isotope effect was observed from the coupling reaction of 3-methoxyphenol with benzaldehyde and 2-propanol/2-propanol-d8 (kH/kD = 2.3 ±0.3). The carbon isotope effect was observed on the benzylic carbon of the alkylation product from the coupling reaction of 3-methoxyphenol with 4-methoxybenzaldehyde (C(3) = 1.021(3)) and on both benzylic and ortho-arene carbons from the coupling reaction with 4-trifluorobenzaldehdye (C(2) = 1.017(3), C(3) = 1.011(2)). The Hammett plot from the coupling reaction of 3-methoxyphenol with para-substituted benzaldehydes p-X-C6H4CHO (X = OMe, Me, H, F, Cl, CF3) displayed a V-shaped linear slope. Catalytically relevant Ru-H complexes were observed by NMR from a stoichiometric reaction mixture of [(C6H6)(PCy3)(CO)RuH]+BF4-, 3-methoxyphenol, benzaldehyde and 2-propanol in CD2Cl2. The DFT calculations provided a detailed catalysis mechanism featuring an electrophilic aromatic substitution of the aldehyde followed by the hydrogenolysis of hydroxy group. The calculations also revealed a mechanistic rationale for strong electronic effect of the aldehyde substrates p-X-C6H4CHO (X = OMe, CF3) in controlling the turnover-limiting step. The catalytic C-H coupling method provided an efficient synthetic protocol for 2-alkylphenols, 1,1-disubstituted benzofurans and xanthene derivatives without employing any reactive reagents or forming wasteful byproducts.
Journal of the American Chemical Society published new progress about Aldehydes Role: RCT (Reactant), RACT (Reactant or Reagent). 1205-17-0 belongs to class isoquinoline, name is 2-Methyl-3-(3,4-methylenedioxyphenyl)propionaldehyde, and the molecular formula is C11H12O3, Quality Control of 1205-17-0.
Referemce:
Isoquinoline – Wikipedia,
Isoquinoline | C9H7N – PubChem