Ligand-Controlled Rhodium-Catalyzed Site-Selective Asymmetric Addition of Arylboronic Acids to ?,?-Unsaturated Cyclic N-Sulfonyl Ketimines.

Title Ligand-Controlled Rhodium-Catalyzed Site-Selective Asymmetric Addition of Arylboronic Acids to ?,?-Unsaturated Cyclic N-Sulfonyl Ketimines.
Authors C.Y. Wu; Y.F. Zhang; M.H. Xu
Journal Org Lett
DOI 10.1021/acs.orglett.8b00289
Abstract

A site-selective rhodium-catalyzed asymmetric 1,4-/1,2-addition of arylboronic acids to challenging ?,?-unsaturated cyclic ketimines was realized through a ligand-controlled strategy. By employing different chiral olefin ligands, a ligand-controlled switch in the reaction regioselectivity was attained for the first time. The reactions allow the synthesis of highly valuable ?,?-disubstituted chiral allylic amines and enantioenriched 1,4-adducts. Further product transformation provided easy access to various quaternary carbon-containing chiral amines and amino acid derivatives bearing multifunctional groups.

Citation C.Y. Wu; Y.F. Zhang; M.H. Xu.Ligand-Controlled Rhodium-Catalyzed Site-Selective Asymmetric Addition of Arylboronic Acids to ?,?-Unsaturated Cyclic N-Sulfonyl Ketimines.. Org Lett. 2018. doi:10.1021/acs.orglett.8b00289

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Boron

See more Boron products. Boron Bohr ModelBoron (atomic symbol: B, atomic number: 5) is a Block P, Group 13, Period 2 element with an atomic weight of 10.81. The number of electrons in each of boron's shells is 2, 3 and its electron configuration is [He] 2s2 2p1. The boron atom has a radius of 90 pm and a Van der Waals radius of 192 pm. Boron was discovered by Joseph Louis Gay-Lussac and Louis Jacques Thénard in 1808 and was first isolated by Humphry Davy later that year. Boron is classified as a metalloid is not found naturally on earth. Elemental BoronAlong with carbon and nitrogen, boron is one of the few elements in the periodic table known to form stable compounds featuring triple bonds. Boron has an energy band gap of 1.50 to 1.56 eV, which is higher than that of either silicon or germanium. The name Boron originates from a combination of carbon and the Arabic word buraqu meaning borax.

Rhodium

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