183130-68-9Relevant academic research and scientific papers
Catalytic intermolecular linear allylic C-H amination via heterobimetallic catalysis
Reed, Sean A.,White, M. Christina
, p. 3316 - 3318 (2008)
A novel heterobimetallic Pd(II)sulfoxide/(salen)Cr(III)Cl-catalyzed intermolecular linear allylic C-H amination (LAA) is reported. This reaction directly converts densely functionalized α-olefin substrates (1 equiv) to linear (E)-allylic carbamates with good yields and outstanding regio- and stereoselectivities (>20:1). Chiral bis-homoallylic and homoallylic oxygen, nitrogen, and carbon substituted α-olefins undergo allylic C-H amination with good yields, excellent selectivities, and no erosion in enantiomeric purity. Streamlined routes to (E)-allylic carbamates that can be further elaborated to medicinally and biologically relevant allylic amines are also demonstrated. Valuable 15N-labeled allylic amines may be generated directly from allyl moieties at late stages of synthetic routes by using the readily available 15N-(methoxycarbonyl)-p-toluenesulfonamide nucleophile. Evidence is provided that this reaction proceeds via a heterobimetallic mechanism where Pd/sulfoxide mediates allylic C-H cleavage to form a π-allylPd intermediate, and (salen)Cr(III)Cl/BQ work together to promote functionalization with the nitrogen nucleophile. Copyright
A catalytic, Bronsted base strategy for intermolecular allylic C-H amination
Reed, Sean A.,Mazzotti, Anthony R.,White, M. Christina
supporting information; experimental part, p. 11701 - 11706 (2009/12/08)
A Bronsted base activation mode for oxidative, Pd(II)/sulfoxide- catalyzed, intermolecular C-H allylic amination is reported. N,N-diisopropylethylamine was found to promote amination of unactivated terminal olefins, forming the corresponding linear allylic amine products with high levels of stereo-, regio-, and chemoselectivity. The predictable and high selectivity of this C-H oxidation method enables latestage incorporation of nitrogen into advanced synthetic intermediates and natural products.
Synthesis of Five-, Six-, and Seven-Membered Heterocycles by Intramolecular Ring Opening Reactions of 3-Oxetanol Derivatives
Bach, Thorsten,Kather, Kristian,Kraemer, Oliver
, p. 1910 - 1918 (2007/10/03)
Intramolecular ring opening reactions of 2-phenyl-3-oxetanols have been studied. The starting materials were prepared by the photocycloaddition of benzaldehyde and various silyl enol ethers. The intramolecular nucleophile was either incorporated into the silyl enol ether prior to the PaternoBuchi reaction (oxetanes 3,16) or was later installed by functional group interconversion (oxetanes 5, 12). With anionic heteroatom nucleophiles (O, N, S) which were attached to the carbon atom C-3 of the trimethylsilyl-protected oxetanol via an alkyl chain, a substitution at the less substituted position C-4 was observed and the corresponding heterocycles (6, 8, 13, 19) were obtained in moderate to good yields (52-91%). Upon acid catalysis a ring opening of the Boc-protected 3-oxetanol 23 to cyclic carbonates occurred. The reaction did not proceed stereospecifically and resulted in a mixture of diastereomeric products 24 and 25.
