Ligand-Controlled, Nickel-Catalyzed Stereodivergent Construction of 1,3-Nonadjacent Stereocenters
Qi Pan1, Kuai Wang1, Weipeng Xu2
1The Institute for Advanced Studies, Wuhan University, Wuhan 430072, China.
Abstract:
In contrast to the asymmetric synthesis of molecules with a single stereocenter or 1,2-adjacent stereocenters, the simultaneous construction of acyclic 1,3-nonadjacent stereocenters via a single catalyst in an enantioselective and diastereoselective manner remains a formidable challenge. Here, we demonstrate the enantioselective and diastereodivergent construction of 1,3-nonadjacent stereocenters through Ni-catalyzed reductive cyclization/cross-coupling of alkene-tethered aryl bromides and α-bromoamides, which represents the major remaining stereochemical challenge of cyclization/difunctionalization of alkenes. Using Ming-Phos as ligand, a diverse set of oxindoles containing 1,3-nonadjacent stereocenters were obtained with high levels of enantio- and diastereoselectivity. Mechanistic experiments and density functional theory calculations indicate that magnesium salt plays a key role in controlling the diastereoselectivity. Furthermore, another set of complementary stereoisomeric products were constructed from the same set of starting materials using Ph-Phox as ligand.
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