Basic instinct: design, synthesis and evaluation of (+)-sparteine surrogates for asymmetric synthesis.
(-)-Sparteine, a naturally occurring lupin alkaloid, is widely used as a chiral ligand for asymmetric synthesis. To address the limitation that sparteine is only available as its (-)-antipode, our group introduced a family of (+)-sparteine surrogates that are structurally similar to (+)-sparteine but lack the D-ring. After briefly summarising the design aspect, this feature article provides an overview of synthetic routes to the sparteine surrogates and a detailed comparison with (-)-sparteine in a range of asymmetric reactions. The main conclusions are: (i) the (+)-sparteine surrogates are most easily prepared starting from (-)-cytisine extracted from Laburnum anagyroides seeds; (ii) in nearly all examples, use of the (+)-sparteine surrogates produced essentially equal but opposite enantioselectivity compared to (-)-sparteine and (iii) the N-Me-substituted (+)-sparteine surrogate is the most useful and versatile of those investigated.
O'Brien
Peter
P
Department of Chemistry, University of York, Heslington, York YO10 5DD, UK. paob1@york.ac.uk
D000470:Alkaloids / Q000737:chemistry; D001392:Azocines / Q000737:chemistry; D018360:Crystallography, X-Ray; D003959:Diamines / Q000737:chemistry*; D015195:Drug Design; D015394:Molecular Structure; D011807:Quinolizines / Q000737:chemistry; D013034:Sparteine / Q000031:analogs & derivatives* / Q000138:chemical synthesis* / Q000737:chemistry; D013237:Stereoisomerism; D000093843:Quinolizidine Alkaloids
D000470:Alkaloids; D001392:Azocines; D003959:Diamines; D011807:Quinolizines; D013034:Sparteine; C004712:cytisine; D000093843:Quinolizidine Alkaloids