Modular and diverse synthesis of amino acids via asymmetric decarboxylative protonation of aminomalonic acids.

Stereoselective protonation is a challenge in asymmetric catalysis. The small size and high rate of transfer of protons mean that face-selective delivery to planar intermediates is hard to control, but it can unlock previously obscure asymmetric transformations. Particularly, when coupled with a preceding decarboxylation, enantioselective protonation can convert the abundant acid feedstocks into structurally diverse chiral molecules. Here an anchoring group strategy is demonstrated as a potential alternative and supplement to the conventional structural modification of catalysts by creating additional catalyst-substrate interactions. We show that a tailored benzamide group in aminomalonic acids can help build a coordinated network of non-covalent interactions, including hydrogen bonds, π-π interactions and dispersion forces, with a chiral acid catalyst. This allows enantioselective decarboxylative protonation to give α-amino acids. The malonate-based synthesis introduces side chains via a facile substitution of aminomalonic esters and thus can access structurally and functionally diverse amino acids.

Distribution of elements extracted from symptom patterns and characteristics of polysomnograph of common symptom patterns of insomnia with Traditional Chinese Medicine.

OBJECTIVE: To analyze the distribution and combined regulation of elements of symptom patterns in the diagnosis of insomnia with Traditional Chinese Medicine (TCM). METHODS: The samples were collected from the patients, diagnosed with insomnia, of Henan Province Hospital of TCM between June 2011 and September 2013. The symptom patterns in insomnia were extracted. Next, symptom differentiation, characteristics of polysomnography (PSG), distribution and combined regulation of these symptom patterns were conducted by tests. RESULTS: In total, 286 eligible patients were recruited. The main locations of the disease symptom elements were the brain and heart, and the main characteristics of the disease symptom elements were phlegm-heat, Yin-deficiency and Qi-stagnation. The elements from two or three symptom patterns were commonly manifested in patients with insomnia, especially from three symptom patterns. We also found that all TCM symptom patterns had an effect on polysomnographic indicators in PSG tests. CONCLUSION: The elements of symptom patterns in insomnia were identified as mainly fire-heat and phlegm-heat. The most common patterns of excess were pathogenic fire derived from stagnation of liver- Qi, and mental disturbance due to phlegm-heat, while the most common patterns of deficiency in both the heart and the spleen. There are many differences in PSG indicators of different syndrome patterns of insomnia.