Reversible nucleophilic addition can lower the observed enantioselectivity in palladium-catalyzed allylic amination reactions with a variety of chiral ligands. Issue 40 (30th September 2015)

• Record Type: Journal Article
• Authors: Caminiti, Nicholas S.; Goodstein, Madison B.; Leibler, Isabelle N.-M.; Holtzman, Bryan S.; Jia, Zitong B.; Martini, Michael L.; Nelson, Nathaniel C.; Bunt, Richard C.
• Is Part Of: Tetrahedron letters. Volume 56:Issue 40(2015)
• Page Start: 5445
• Page End: 5448
• Publication Date: 2015-09-30
• Subjects: Enantioselective -- Palladium catalysis -- Allylic amination -- Reversibility -- Chiral ligand; Chemistry, Organic -- Periodicals; 547.005
• DOI: 10.1016/j.tetlet.2015.08.010
• Languages: English
• ISSNs: 0040-4039

Abstract

Graphical abstract: Abstract: Palladium-catalyzed allylic amination is an important synthetic reaction that is also frequently used as a benchmark for the design and evaluation of new chiral ligands. The effect of reversible nucleophilic addition on the reaction of benzylamine with ( E )-1, 3-diphenylallyl ethyl carbonate (1 ) in CH2 Cl2 was examined with 12 different chiral ligands across a range of scaffolding types. In 8 out of 12 cases the observed ee was significantly higher when DBU or Cs2 CO3 was added to suppress the proton-driven reversibility. For chiral ligand screening with this test reaction, adding DBU or Cs2 CO3 provides a better measure of the ligand's inherent enantioselectivity.