A new platinum(II)-catalyzed asymmetric ring-opening addition of arylboronic acids to oxabenzonorbornadienes was developed, which afforded the corresponding cis-2-aryl-1,2-dihydronaphthalen-1-ol products in high yields (up to 97%) with moderate to good enantioselectivities (up to 89% ee) under very mild conditions. The effects of various ligands, catalyst loading, bases, solvents, and temperatures on the yield and enantioselectivity of the reaction were also investigated. The cis configuration of product 2m was confirmed by X-ray diffraction analysis. A potential mechanism for the present catalytic reaction is proposed.
A new, versatile, and highly efficient nickel-catalyzed asymmetric ring-opening (ARO) reaction of oxabenzonorbornadienes with a wide variety of arylboronic acids has been developed, yielding cis-2-aryl-1,2-dihydronaphthalen-1-ols in high yields (up to 99%) with good to excellent enantioselectivities (up to 99% ee) under very mild conditions. The effects of various nickel precursors, chiral bidentate ligands, catalyst loadings, bases, solvents, and temperatures on the yield and enantioselectivity of the reaction were also investigated. A plausible mechanism was proposed to account for the formation of the corresponding cis-ring-opened products based on the X-ray structure of product 4b.
A platinum(II)-catalyzed asymmetric ring opening of oxabenzonorbornadienes with phenols was developed, which afforded the corresponding cis-2-(un)substituted phenoxy-1,2-dihydronaphthalen-1-ol products rather than the trans ones in excellent yields (up to 99%) with moderate to good enantioselectivities (up to 87% ee) under mild conditions. In addition, the cis-configuration of product 2b was confirmed by X-ray diffraction analysis. Based on the results, a potential mechanism for the present catalytic reaction was proposed.
Nickel-Catalyzed Asymmetric Ring Opening of Oxabenzonorbornadienes with Arylboronic Acids. -In comparison to related transition metal-catalyzed protocols, this procedure is characterized by utilization of a cheaper catalyst precursor, low catalyst loading, higher efficiency, enantioselectivity, and functional group tolerance. -(ZENG, Z.; YANG*, D.; LONG, Y.; PAN, X.; HUANG, G.; ZUO, X.; ZHOU, W.; J. Org. Chem. 79 (2014) 11, 5249-5257, http://dx.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.