Palladium-Catalyzed Oxidative Rearrangement of Tertiary Allylic Alcohols to Enones with Oxygen in Aqueous Solvent

Abstract

A one-pot procedure for Pd(TFA)2-catalyzed 1,3-isomerization of tertiary allylic alcohols to secondary allylic alcohols followed by a Pd(TFA)2/neocuproine-catalyzed oxidative reaction to β-disubstituted-α,β-unsaturated kenones was developed.

Synthesis of Substituted Benzoxacycles via a Pd(II)‐Catalyzed Intramolecular Arylation Reaction of Allylic Alcohols

“…The generated allylic carbocation then partakes in an intramolecular Friedel-Crafts reaction to afford product IV. The proposed mechanism is consistent with earlier reports [11,13] concerning the Pd-catalyzed dehydration of allylic alcohols to form anallylic carbocation complex as an active species to initiate the downstream reactions. To support our proposed mechanism, we conducted a reaction where enantiomerically enriched substrate 3o (92% ee) was treated with the Pd-catalyst under the optimized conditions.…”

“…A previous report concerning the Pd-catalyzed isomerization of allylic alcohols [11] identified Pd(TFA) 2 as an effective catalyst for the isomerization of allylic alcohols. We therefore selected Pd(TFA) 2 as a catalyst for the proposed Friedel-Crafts reaction.…”

“…(1)] ( Figure 1). [11] We later found that Pd-catalyzed carbonylative cyclizations of aryl alkenes/alkenols were an effective method for the synthesis of structurally diverse chromanes [Eq. (2), Figure 1].…”

Enantioselective synthesis of compounds containing bis-benzylic quaternary stereocenters through palladium-catalyzed conjugate additions of arylboronic acids

“…were prepared according to a literature procedure. 18 Characterization data for 3-(4-methoxyphenyl)-cyclohex-2-enone 1a, 19 3-phenylcyclohex-2-enone 1b, 18 3-(4-fluorophenyl)cyclohex-2-enone 1c, 20 3-(4-methylphenyl)-cyclohex-2-enone 1d, 19 3-(4-methoxyphenyl)cyclopent-2-enone 1e, 21 3-(4-trifluoromethylphenyl)-cyclohex-2-enone 1f, 22…”

“…cyclohex-2-enone 1g, 20 and 3-(2-methoxyphenyl)-cyclohex-2-enone 1h20 matched previously reported data. 3-(3-Pyridyl)-cyclohex-2-enone 1i,23 (E)-4phenylcyclohept-2-enone 1j,22 (E)-4-phenylpent-3-en-2-one 1k24 were synthesized according to reported literature procedures. (4R,4'R)-2,2'-(propane-2,2-diyl)bis(4-phenyl-4,5dihydrooxazole) ((R)-PhBox),25 (S)-4-(tert-butyl)-2-(pyridin-2-yl)-4,5-dihydrooxazole ((S)-t-BuPyOx),26 and (S)-4-isopropyl-2-(pyridin-2-yl)-4,5-dihydrooxazole ((S)-i-PrPyOx)27 were prepared according to previously reported literature procedures.…”