Ni(II) bis(oxazoline)-catalyzed enantioselective syn aldol reactions of N-propionylthiazolidinethiones in the presence of silyl triflates.
An enantioselective aldol reaction of N-propionylthiazolidinethione and representative aldehydes is disclosed. The reaction is catalyzed by [Ni(S,S)-t-BuBox](Otf)2. Enolization is effected by 2,6-lutidine, and TMSOTf facilitates catalyst turnover. Syn diastereoselectivities range from 88:12 to 97:3, and enantioselectivities are 90% or greater. Both aromatic and enolizable aliphatic aldehydes are included within the scope of this aldol addition process.
Evans
David A
DA
Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, USA. evans@chemistry.harvard.edu
Downey
C Wade
CW
Hubbs
Jed L
JL
D000438:Alcohols / Q000138:chemical synthesis*; D007659:Ketones / Q000138:chemical synthesis / Q000737:chemistry*; D008958:Models, Molecular; D009532:Nickel / Q000737:chemistry*; D009942:Organometallic Compounds / Q000737:chemistry; D010080:Oxazoles / Q000737:chemistry*; D012821:Silanes / Q000737:chemistry*; D013237:Stereoisomerism; D013844:Thiazoles / Q000737:chemistry*
D000438:Alcohols; D007659:Ketones; D009942:Organometallic Compounds; D010080:Oxazoles; D012821:Silanes; D013844:Thiazoles; C411864:silyl trifluoromethanesulfonate; C064210:oxazolidine; D009532:Nickel