Diastereoselective synthesis of α, α, α′-trisubstituted pyrrolidines and piperidines by directed sequential lithiation/alkylation. Issue 1 (1st January 2015)

• Record Type: Journal Article
• Authors: Beng, Timothy K.; Fox, Nathan
• Is Part Of: Tetrahedron letters. Volume 56:Issue 1(2015)
• Page Start: 119
• Page End: 122
• Publication Date: 2015-01-01
• Subjects: Directed lithiation -- Trisubstituted pyrrolidines -- Trisubstituted piperidines -- Diastereoselective alkylation -- Electrophilic substitution; Chemistry, Organic -- Periodicals; 547.005
• DOI: 10.1016/j.tetlet.2014.11.031
• Languages: English
• ISSNs: 0040-4039

Abstract

Graphical abstract: Abstract: The stereocontrolled synthesis of α, α, α′-trisubstituted pyrrolidines and piperidines has been accomplished through α′-lithiation/trapping of the corresponding α, α-disubstituted Boc-protected azaheterocycle with various electrophiles. The relative configuration of the major diastereomer has the α′-substituent trans to the α-aryl group in the pyrrolidines but cis to the α-aryl group in the piperidines. The diastereoselectivity of the lithiation/alkylation of pyrrolidines is unaffected by TMEDA but decreases in the presence of (−)-sparteine in diethyl ether.