Sterically Hindered, Electron-rich Mop Ligands Of Synthetic Route Optimization And In The Palladium-catalyzed Carbon Hybrid Bond Formation

Palladium-catalyzed C-N bond forming reactions have evolved into a versatile and efficient synthetic transformation. Existing catalyst system showed high activity for assisting the palladium-catalyzed amination of reaction of aryl halides, thus one of the major challenged confronted in the development of more efficient catalysts in inexpensive and simple to synthesis and reading accessible liangds.A series of 2-dialkylphosphino-2'-alkoxy-1,1'-binaphthyl ligands (6a-c, and 8a-c) have been prepared conveniently by lithium initiated ring-opening reaction of dinaphthofuran, followed by selective phosphorylation. These compounds displayed a remarkable air and moisture stability, both in solid form and in solution.The bulky and electron-rich MOP-type ligands shows high efficiency for the coupling reaction of amino acids and inactive aryl halides to give N-aryl amino acids. Under the catalytic conditions, not only a-amino acids but alsoβ-,γ, andδ-amino acids have been coupled with aryl chlorides in high yields, in the case of optically pure amino acids as substrates, the coupling products ofβ-amino acids retain high optical purity.We also developed a simple and efficient one-pot, two step method for synthesis of 2'-functionalized 1, 1'-binaphthyl-2-ols by reductive ring-opening of binaphthofuran (1) with lithium to give the C,O-dilithium reagent (2), followed by reacting it with the corresponding electrophiles to give 2'-functionalized 1, 1'-binaphthyl-2-ols including the halides (3), amine (4), acid (5), aldehyde (6), carbonate (7) or phosphonate (8), respectively, in moderate to good yields.