One-Pot Synthesis of γ,δ-Unsaturated Carbonyl Compounds from Allyl Alcohols and Vinyl or Isopropenyl Acetates Catalyzed by [IrCl(cod)]₂

Abstract

One-pot synthesis of gamma,delta-unsaturated carbonyl compounds from allyl alcohols and vinyl or isopropenyl acetates was achieved through in situ generation of allyl vinyl ethers by the action of the [IrCl(cod)]2 complex followed by Claisen rearrangement of the resulting ethers. For instance, the reaction of trans-2-methyl-3-phenyl-2-propen-1-ol with isopropenyl acetate in the presence of [IrCl(cod)]2 (1 mol %) and Cs2CO3 (5 mol %) at 100 degrees C for 3 h followed by 140 degrees C for 15 h afforded 5-methyl-4-phenyl-5-hexen-2-one in 72% yield. When vinyl acetate was employed in place of isopropenyl acetate, 4-methyl-3-phenyl-4-pentenal was obtained in 83% yield.

Visible Light Mediated Photocatalytic N-Radical Cascade Reactivity of γ,δ-Unsaturated N-Arylsulfonylhydrazones: A General Approach to Structurally Diverse Tetrahydropyridazines

“…Following the described procedure, 0.98 g (10.0 mmol) of mesityl oxide 6i (4-methylpent-3-en-2-one) were reacted with CuI and vinylmagnesium bromide 7a to afford 1.12 g of 4,4-dimethylhex-5-en-2-one 8i (89%) as a colorless oil …”

“…Following the described procedure, 0.98 g (10.0 mmol) of mesityl oxide 6i (4-methylpent-3-en-2one) were reacted with CuI and vinylmagnesium bromide 7a to afford 1.12 g of 4,4-dimethylhex-5-en-2-one 8i (89%) as a colorless oil. 95 1 2,2-Dimethylpent-3-enylphenone (8j). Following the described procedure, 1.60 g (10.0 mmol) of 2-methylprop-1-enylphenone 6a (4methylpent-3-en-2-one) were reacted with CuI and propenylmagnesium bromide 7b to afford 1.75 g of 2,2-dimethylpent-3-enylphenone (8j) (87%) as a colorless oil.…”

Iridium-Catalyzed Reactions Involving Transfer Hydrogenation, Addition, N-Heterocyclization, and Alkylation Using Alcohols and Diols as Key Substrates

“…intermediate 16 (Scheme 6), followed by Claisen rearrangement of the resulting ether. 45 Thus, the reaction of trans-2-methyl-3-phenylprop-2-en-1-ol (14) (0.5 mmol) with isopropenyl acetate (15) (6 mmol) in the presence of [IrCl(cod)] 2 (2 mol%) and Cs 2 CO 3 (5 mol%) at 100 °C for 3 hours, followed by the reaction at 140 °C for 15 hours, afforded 5-methyl-4-phenylhex-5-en-2-one (17) in 83% yield (Scheme 6).…”

“…intermediate 16 (Scheme 6), followed by Claisen rearrangement of the resulting ether. 45 Thus, the reaction of trans-2-methyl-3-phenylprop-2-en-1-ol ( 14…”

Direct Synthesis of anti-1,3-Diols through Nonclassical Reaction of Aryl Grignard Reagents with Isopropenyl Acetate

“…Acetylacetone (β-diketone) is produced by isomerization of isopropenyl acetate under heating (450−500 °C) in the presence or absence of catalyst . From our results, it is obvious that this isomerization did not take place in the reaction of isopropenyl acetate with various Grignard reagents.…”