The first transition metal-free highly stereoselective positional isomerization of various α-alkyl styrenes through a carbocation mechanism triggered strategy is developed by using Al(OTf)3 as a hidden Brønsted acid catalyst, which provides facile access to value-added acyclic tri- and tetra-substituted alkenes in good yields with high stereoselectivity under mild conditions. The practicality of this
Iron Catalyzed Isomerization of
<scp>α‐Alkyl</scp>
Styrenes to Access Trisubstituted Alkenes
作者:Songgen Xu、Guixia Liu、Zheng Huang
DOI:10.1002/cjoc.202000492
日期:2021.3
supported by phosphine‐pyridine‐oxazoline (PPO) ligand. The protocol provides an atom‐efficient and operationally simple approach to trisubstituted alkenes in high yields with excellent regio‐ and stereoselectivities under mild conditions. The results of deuterium‐labelling and radical trap experiments are consistent with an iron‐hydride pathway involving reversible alkene insertion and β‐H elimination.
Cobalt-Catalyzed Migrational Isomerization of Styrenes
作者:Jiajin Zhao、Biao Cheng、Chenhui Chen、Zhan Lu
DOI:10.1021/acs.orglett.9b04305
日期:2020.2.7
An efficient cobalt-catalyzed migrational isomerization of styrenes was developed using the thiazoline iminopyridine (TIP) ligand. This reaction is operationally simple and atom economical using readily available starting materials to access trisubstituted alkenes. Even when using a 0.1 mol % catalyst loading, the reaction could be conducted in neat and completed in 1 h with excellent conversion and high E stereoselectivity.
Photochemistry of (o-methylphenyl)alkenes and the stereospecific trapping of the resulting o-xylylenes