Recalcitrant SN2 Displacements at Carbon C9 of Quincorine and Quincoridine: 1,2-Amino Halides and Mesylates with Configurationally Rigid Nitrogen

SN2 reactions at carbon C9 of Quincorine (QCI) and Quincoridine (QCD) were investigated and found to be difficult, due to the special structural (‘β-amino effect’) and conformational factors. Efficient experimental procedures for displacement with a variety of carbon and heteroatom nucleophiles were developed.