Gou Bo-Bo, Tang Yue, Lin Yan-Hong, Yu Le, Jian Qing-Song, Sun Huai-Ri, Chen Jie, Zhou Ling
Key Laboratory of Synthetic and Natural Functional Molecule of the Ministry of Education, College of Chemistry & Materials Science, National Demonstration Center for Experimental Chemistry Education, Northwest University, Xi'an, 710127, P. R. China.
Angew Chem Int Ed Engl. 2022 Oct 4;61(40):e202208174. doi: 10.1002/anie.202208174. Epub 2022 Aug 29.
Here we report a new type of chiral all-carbon tetrasubstituted VQMs generated via chiral phosphoric acids catalyzed nucleophilic addition of 2-alkynylnaphthols to o-quinone methides or imines, which can be captured intramolecularly as a result of cycloaddition reaction. A new class of naphthyl-2H-chromenes bearing axially and centrally chiral elements and axially chiral quinone-naphthols were prepared efficiently with good to excellent yields, diastereoselectivities and enantioselectivities. Noteworthy, the enantioselective cycloaddition of alkynylnaphthols with o-quinone methides proceeded via a [2+2] cycloaddition, followed by a retro-4π-electrocyclization and a 6π re-cyclization. While the cycloaddition of alkynylnaphthols with imines proceeded via a sequential [2+4] cycloaddition and an auto oxidation reaction. Moreover, the obtained axially chiral naphthols can be converted into valuable phosphine ligands and other functional molecules.
在此，我们报道了一种新型的手性全碳四取代VQMs，它是通过手性磷酸催化2-炔基萘酚与邻醌甲基化物或亚胺的亲核加成反应生成的，由于环加成反应，其可以在分子内被捕获。一类带有轴向和中心手性元素的新型萘基-2H-色烯以及轴向手性醌-萘酚得以高效制备，产率良好至优异，具有非对映选择性和对映选择性。值得注意的是，炔基萘酚与邻醌甲基化物的对映选择性环加成反应通过[2+2]环加成进行，随后是逆4π-电环化和6π再环化。而炔基萘酚与亚胺的环加成反应则通过连续的[2+4]环加成和自动氧化反应进行。此外，所得到的轴向手性萘酚可以转化为有价值的膦配体和其他功能分子。
