Enantioselective Pt-Catalyzed Diboration of Unsaturated Hydrocarbons
Kliman, Laura Taraday. “Enantioselective Pt-Catalyzed Diboration of Unsaturated Hydrocarbons”, Boston College, 2011. http://hdl.handle.net/2345/2457.
Platinum-catalyzed enantioselective diboration of various hydrocarbon starting materials to form stereodefined carbon-boron bonds is reported. The asymmetric Pt-catalyzed 1,4-diboration of trans-1,3-dienes provided 1,4-bis(boronate)esters in up to 98:2 er, representing the first enantioselective diene diboration. The enantioselective 1,2-diboration of cis-1,3-dienes and 4,4-disubstituted dienes afforded 1,2-bis(boronate)esters in up to 98:2 er. The intermediate allylboronates were utilized in aldehyde allylations to furnish polypropionate-like compounds and stereodefined carbon quaternary centers. The development of a Pt-catalyzed enantioselective diboration of terminal olefins is disclosed, giving the corresponding 1,2-diols in up to 97:3 er. Further optimization and expansion of the scope of this method is also discussed.