1447951-45-2Relevant academic research and scientific papers
Asymmetric cascade annulation based on enantioselective oxa-diels-alder cycloaddition of in situ generated isochromenyliums by cooperative binary catalysis of Pd(OAc)2 and (S)-trip
Yu, Shu-Yan,Zhang, Hao,Gao, Yang,Mo, Lei,Wang, Shaozhong,Yao, Zhu-Jun
supporting information, p. 11402 - 11407 (2013/08/23)
An asymmetric cascade annulation between 2-hydroxystyrenes and 2-alkynylbenaldehyes or 1-(2-alkynylphenyl)ketones has been established with good to excellent enantioselectivities (up to >99.5% ee), on the basis of an enantioselective oxa-Diels-Alder cycloaddition of in situ generated metallo-isochromenylium intermediates, by cooperative binary catalysis of Pd(OAc)2 and (S)-Trip. The developed methodology is workable for a broad spectrum of substrates and shows great efficiency in establishing dense multiple chiral centers including quaternary carbons of variable bridged ring systems. The mechanism study suggests that (S)-Trip plays multiple roles in assembling the reactants and controlling the stereoselectivity.
