6533b852fe1ef96bd12ab635
RESEARCH PRODUCT
Chiral Brønsted Acid-Catalyzed Asymmetric Allyl(propargyl)boration Reaction of ortho-Alkynyl Benzaldehydes: Synthetic Applications and Factors Governing the Enantioselectivity
Pablo BarrioK. N. HoukAmparo AsensioElsa RodríguezSantos FusteroMatthew N. Graysonsubject
chemistry.chemical_classification010405 organic chemistryStereochemistrySubstituentAlkyneGeneral Chemistry010402 general chemistryEnyne metathesisTriple bond01 natural sciencesCatalysis0104 chemical scienceschemistry.chemical_compoundchemistryOrganocatalysisIntramolecular forcePropargylHydroalkoxylationdescription
Chiral Bronsted acid-catalyzed allyl(propargyl)boration of ortho-alkynyl benzaldehydes gives rise to ω-alkynyl homoallylic(homopropargylic)alcohols that can be further transformed to complex molecular scaffolds via subsequent hydroalkoxylation, ring-closing enyne metathesis (RCEYM), or intramolecular Pauson–Khand reaction (PKR). Optimizations of each two-step transformation is reported. A strong dependence between enantioselectivities and the nature of the substitution at the alkynyl moiety is observed, showcasing that the triple bond is not merely a spectator in this transformation. Density functional theory (DFT) calculations (M06-2X/6-311+G(d,p)–IEFPCM//B3LYP/6-31G(d)) show that this dependence is the result of the steric and electronic properties of the alkyne substituent.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2016-03-15 | ACS Catalysis |