The formation of heterocyclic amines (HAs) in a model system during heating at 100, 150, or 200 degrees C for varied lengths of time was studied. The following systems were used: (i) phenylalanine, (ii) creatinine, (iii) phenylalanine and glucose, (iv) phenylalanine and creatinine, (v) glucose and creatinine, and (vi) phenylalanine, glucose, and creatinine. Results showed that HAs could only be found in both systems of glucose and creatinine, and of phenylalanine, glucose, and creatinine. Both 2-amino-9H-pyrido-[2,3-b]indole (AalphaC) and 2-amino-3-methyl-9H-pyrido-[2,3-b]indole (MeAalphaC) were observed in the former system, and the formation rate of AalphaC was higher than MeAalphaC. For the latter system, 2-amino-3-dimethylimidazo[4,5-f]quinoxaline (IQx), 9H-pyrido-[4,3-b]indole (Norharman), 1-methyl-9H-pyrido-[4,3-b]indole (Harman), AalphaC, and MeAalphaC were present. The formation rate of AalphaC was the highest at 200 degrees C, followed by MeAalphaC, Harman, Norharman, and IQx. In addition, the varieties of HAs increased both with increasing heating time and temperature. The amounts of HAs formed were less in the model system of glucose and creatinine than that of phenylalanine, glucose, and creatinine. The same trend was also observed for the formation rate of HAs. At 150 or 200 degrees C, the amounts of IQx, Harman, Norharman, AalphaC, and MeAalphaC increased in the initial period of heating and then reached a plateau. The results of this study provided a basic understanding of the conditions that result in the formation of HAs during cooking of meat and fish products.

A synthetic strategy for the catalytic asymmetric total synthesis of (-)-actinophyllic acid is described. This highly efficient and enantioselective approach allows the rapid installation of the four contiguous chiral centers (C16, C15, C20, and C19) by way of a dual Ir/amine catalytic allylation of 2-indolyl vinyl carbinol 6 and an aldol reaction of resultant chiral aldehyde 4a with 2-pyrrolidinone 5. The key indol-3-ylmethanamine moiety and 1-azabicyclo[4.2.1]nonane ring system were readily generated through a selective Mannich-like cyclization and an intramolecular N-alkylation, respectively.

Ir-catalyzed enantioselective allylic alkylation of branched racemic allylic alcohols with malonates is described. Enabled by Carreira’s chiral Ir/(P, olefin) complex, the method described allows allylic substitution with various aromatic alcohols and malonates with excellent enantioselectivity. The malonates could be used directly as efficient nucleophiles without the need of preactivation.