Dasheng Leow, Shishi Lin, Santhosh Kumar Chittimalla Dr., Xiao Fu, Choon‐Hong Tan Prof.
Angew. Chem. Int. Ed. 2008, 47, 5641–5645. (Highlighted in Synfacts 2008, 9, 0933-0933; contributors: Benjamin List, Frank Lay; Highlighted in ChemInform 2008, 39, DOI: 10.1002/chin.200847194.)
Abstract: Simple is beautiful: The guanidine derivative 1 catalyzes a tandem conjugate addition–enantioselective protonation reaction of phthalimidoacrylates with thiols (see scheme) and itaconimides with phosphine oxides. Optically pure analogues of cysteine and cystine were obtained in this way. In highly enantioselective deuteration reactions, a small but significant kinetic isotope effect was observed. R=aryl, benzhydryl; R1–R4=H, Me, Cl, F.
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