Direct Oxidation of β‐Aryl Substituted Aldehydes to α,β‐Unsaturated Aldehydes Promoted by an o‐Anisidine–Pd(OAc)₂ Co‐catalyst

Abstract

An o-anisidine-Pd(OAc)2 catalytic system for the direct co-catalytic Saegusa oxidation of beta-aryl substituted aldehydes to alpha,beta-unsaturated aldehydes has been developed. The use of o-anisidine in place of (S)-diphenylprolinol made the process more simply and cost-effective. The process not only features the use of unmodified aldehydes rather than enol silyl ethers, but also gives moderate to good yields (44-72%).

Highly Enantioselective Synthesis of Functionalized Glutarimide Using Oxidative N-Heterocyclic Carbene Catalysis: A Formal Synthesis of (−)-Paroxetine

“…The product was prepared according to GP-I from the corresponding α,β-unsaturated alcohol (300.0 mg) to afford 1m (210.0 mg) as a pale yellow solid in 71% yield (step 3). Spectroscopic data are in good agreement with reported values …”

Aromatic and Aliphatic Apiuronides from the Bark of Cinnamomum cassia

“…By comparing the spectroscopic data (mainly 1 H and 13 C NMR) with reported data, the known compounds were identified as cinnzeylanol ( 8 ), cinnacaside ( 9 ), kelampayoside A ( 10 ), syringaresinol ( 11 ), cinnzeylanin, anhydrocinnzeylanol, anhydrocinnzeylanine, 2-methoxycinnamaldehyde, 2-hydroxycinnamaldehyde, cinnamyl alcohol, cinnamic acid, 2-hydroxycinnamyl alcohol, coniferyl aldehyde, rosavin, (2 E )-3-phenyl-2propen-1-yl 6- O -β- D -xylopyranosyl-β- D -glucopyranoside, 1-phenyl-1,2,3-propanetriol, guaiacylglycerol, guaialcylglycerol 7- O-β - D - glucopyranoside, erythro -syringylglycerol, dihydrocinnacasside, cryptamygin C, 3,4-dimethoxyphenyl 1- O - D -apio-β- D -furanosyl-β- D -glucopyranoside, canthoside C, cinnacassosides C, coumarin, benzoic acid, syringaldehyde, (−)-lyoniresinol 2α- O -β- D -glucopyranoside, (4 R )-4-hydroxy-1,10- seco -muurol-5ene-1,10-dione, decumbic acid, and {[(6- O -(β- D -apiofuranosyl)-β- D -glucopyranosyl]­oxy}­propane (Figure S59, Supporting Information) …”

“…By comparing the spectroscopic data (mainly 1 H and 13 C NMR) with reported data, the known compounds were identified as cinnzeylanol (8), 34 cinnacaside (9), 35 kelampayoside A (10), 23 syringaresinol (11), 36 cinnzeylanin, 34 anhydrocinnzeylanol, 37 anhydrocinnzeylanine, 38 2-methoxycinnamaldehyde, 39 2-hydroxycinnamaldehyde, 40 cinnamyl alcohol, 41 cinnamic acid, 32 2-hydroxycinnamyl alcohol, 42 coniferyl aldehyde, 43 rosavin, 44 (2E)-3-phenyl-2propen-1-yl 6-O-β-Dxylopyranosyl-β-D-glucopyranoside, 44 1-phenyl-1,2,3-propanetriol, 42 guaiacylglycerol, 45 guaialcylglycerol 7-O-β-D-glucopyranoside, 46 erythro-syringylglycerol, 45 dihydrocinnacasside, 19 cryptamygin C, 29 3,4-dimethoxyphenyl 1-O-D-apio-β-D-furanosyl-β-D-glucopyranoside, 23 canthoside C, 47 cinnacassosides C, 23 coumarin, 48 benzoic acid, 49 syringaldehyde, 50 (−)-lyoniresinol 2α-O-β-D-glucopyranoside, 51 (4R)-4-hydroxy-1,10-secomuurol-5ene-1,10-dione, 52 decumbic acid, 53 Analgesic Effects of the Isolates. Among the isolates from the bark of C. cassia, cinnzeylanol (8), cinnacaside (9), kelampayoside A (10), syringaresinol (11), cinnzeylanin, cryptamygin C, 3,4-dimethoxyphenyl 1-O-D-apio-β-D-furanosyl-β-D-glucopyranoside, and syringaldehyde were evaluated for their analgesic effects in a paclitaxel-induced cold allodynia mice model.…”

Iron-Catalyzed α,β-Dehydrogenation of Carbonyl Compounds

“…Recently, catalytic approaches using transition metals, especially palladium, have been well demonstrated as efficient and powerful tools for the α,β-desaturation of a wide range of carbonyl compounds. − Other transition metals including copper, , ruthenium, platinum, iridium, and nickel have also been successfully applied as the catalyst (Scheme a).…”