Visible-light-induced radical cascade cyclization of oxime esters and aryl isonitriles: synthesis of cyclopenta[b]quinoxalines.

A visible-light-induced radical cascade cyclization of aryl isonitriles and cyclobutanone oxime esters for the synthesis of cyclopenta[b]quinoxalines has been accomplished for the first time. The key to the success of this process was the integration of the in situ-formed nitrile radical followed by the cascade radical isonitrile/nitrile insertion-cyclization. The easy introduction of substituents for both substrates and the high functional group tolerance of the reaction make it an efficient strategy to give various quinoxaline derivatives in moderate to good yields.

Acetic acid lignins from Chinese quince fruit (Chaenomeles sinensis): effect of pretreatment on their structural features and antioxidant activities.

In this study, three pretreatment processes were evaluated for their effects on the structural features and antioxidant activities of lignins extracted by the acetosolv process from the fruit of Chinese quince. The three pretreatments included dephenolization, sugar removal, and multiple processes (a combination of both dephenolization and sugar removal). The results showed that after sugar removal pretreatment, the carbohydrate content, the molecular weight and S/G value of the lignin fractions decreased. However, after dephenolization pretreatment, the carbohydrate content and the molecular weight of the lignin fractions increased. After sugar removal and dephenolization, there were increases in the temperatures corresponding to the maximal rate of decomposition (DTGmax) in all lignin fractions. The radical scavenging index of lignin after sugar removal pretreatment was higher compared to other pretreatments and no treatment. The results of these tests showed that sugar removal, as a pretreatment, enhanced lignin extraction, yielding pure and highly functional lignins. Additionally, dephenolization or multiple process were beneficial to the acquisition of macromolecular lignins. All the results provided references for the biorefinery of biomass rich in polyphenol and sugar compounds.

Visible-Light-Induced Decarboxylative Functionalization of Carboxylic Acids and Their Derivatives.

Visible-light-induced radical decarboxylative functionalization of carboxylic acids and their derivatives has recently received considerable attention as a novel and efficient method to create CC and CX bonds. Generally, this visible-light-promoted decarboxylation process can smoothly occur under mild reaction conditions with a broad range of substrates and an excellent functional-group tolerance. The radical species formed from the decarboxylation step can participate in not only single photocatalytic transformations, but also dual-catalytic cross-coupling reactions by combining photoredox catalysis with other catalytic processes. Recent advances in this research area are discussed herein.

[A survey on knowledge of recommended heart failure guidelines among Chinese physicians].

OBJECTIVE: To obtain the knowledge status on recommended heart failure (HF) guidelines among Chinese physicians. METHODS: Questionnaire on heart failure including 20 multiple choice questions and 10 fill in the blank questions was designed based on the Chinese guidelines for the diagnosis and treatment of chronic heart failure in 2007 and the Chinese guidelines for the diagnosis and treatment of acute heart failure in 2010. The rate of correct answer for each item was calculated and compared among physicians specialized for cardiovascular diseases and not. RESULTS: The Questionnaire was completed in 400 physicians, including 208 physician specialized for cardiovascular disease and 192 physicians not specialized in cardiovascular disease. The rate of correct answer for 20 multiple choice questions was lower than 60% in 8 questions, 60%-80% in 8 questions, higher than 80% in 4 questions. The rate of correct answers for 10 fill in the blank questions focusing on the aimed dosage of 10 ACEI/ARB/ß-blockers was 49%. The 8 multiple choice questions with correct answer rate <60% are detailed items of myocardial remodeling, symptoms suggestive of HF, diagnosis tools for patients with suspected HF, the AHA stages of heart failure, the Forrester's hemodynamic classes of acute heart failure, the goals of ACEI/ARBs treatment in patients with HF, names of heart diseases which might benefit from ACEI/ARBs treatment defined by evidenced based medicine, and detailed application methods of ACEI/ARBs and ß-blockers for HF patients. In general, the rate of correct answer was significantly higher in physicians specialized for cardiovascular disease compared physicians not specialized for cardiovascular disease. CONCLUSION: There is a considerable knowledge gap on the Chinese guidelines for the diagnosis and treatment of chronic heart failure and the Chinese guidelines for the diagnosis and treatment of acute heart failure among Chinese physicians. Efforts must be made to educate physicians to improve their knowledge and improve HF patient care.