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 (): 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.

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.

[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.