Fig. 6: NHC-catalyzed racemization-free peptide synthesis.
From: Stereoselective diversification of α-amino acids enabled by N-heterocyclic carbene catalysis
A Standard conditionsa for control experiment: a mixture of chiral AAs 1ab (0.05 mmol), amine 2b (0.055 mmol), NHC-7a (20 mol%) and DIC (0.06 mmol) dissolved in DCM (0.05 M) was stirred at r.t. for 3–6 h. Isolated yields are presented. Chiral HPLC determined de and es values, see Supplementary Fig. S6. bCompounds 1ab and 2b dissolved in DCM (0.05 M) were stirred at r.t. c,dFor concrete operations, see Supplementary Figs. S9 and S10. B Application in peptite synthesis. eStd. cond. C: step 1: MYTsA (1.2 eq.) in DCM; step 2: H-L-Phe-OMe.HCl (1.1 eq.) in DMF, see Supplementary Fig. S11. fFor concrete operations, see Supplementary Fig. S12.
