Homoallylboration of Aldehydes: Stereoselective Synthesis of Allylic-Substituted Alkenes and E-Alkenes
2022
Polyak, Daniel | Xu, Bokai | Krauss, Isaac
Cyclopropanated allylboration reagents participate in the homoallylation of aliphatic and aromatic aldehydes, generating substituted alkenes that are difficult to produce via other methods. In this study, we explored the scope and reactivity of homoallylation with cyclopropylcarbinylboronates bearing various aliphatic and aromatic α- and γ-substituents. α-Alkyl substituted boronates afforded E-disubstituted alkenyl secondary alcohols in high enantiomeric ratios, while aryl substituents promoted rearrangement. γ-Alkyl substituents all resulted in diastereoselective homoallylation, while aryl substitution changed the outcome to cyclopropylcarbinylation.
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