A copper-catalyzed process for the synthesis of pyrrolo[1,2-a]quinoxalines from readily available α-amino acids and 1-(2-halophenyl)-1H-pyrroles is described. Different functional groups were well tolerated to give the corresponding products.
A copper-catalysed three-component reaction for constructing a series of quinazoline derivatives has been developed. In this system, solvents act as the reactants and different functional groups are well tolerated to obtain corresponding products in moderate to good yields.
A one-pot protocol for the synthesis of structurally diverse 2-hetarylbenzothiazoles via oxidative condensation of the sp C-H bond with benzothiazoles has been described. This process is metal free and operationally simple. A series of 2-hetarylbenzothiazoles were prepared in moderate to good yield under mild conditions.
Lipreading is a type of Human–Computer Interaction (HCI) based on visual information. From a linguistic point of view, Chinese is a monosyllabic language with a much higher proportion of homophones than English. Identifying homophones in Chinese Mandarin lipreading is very challenging. Since the lip shape in the context can distinguish homophones, and smaller recognition units can reduce the types of recognition and alleviate data sparsity, we propose to improve the accuracy of lipreading by simultaneously exploiting the correlation of lip features at different distances and smaller modeling units. We implement a long short-term multi-feature space to represent lip features, and CTC–Attention to learn temporal correlations. We also introduce Weight Finite State Transducer (WFST) to enhance the semantic analysis capability of the model. Our model aims to distinguish homophones and improve the accuracy of lipreading. To reduce data sparsity, we use Tonal Initials and Finals (TIF) as the modeling units. We record a sentence-level Chinese lipreading dataset, ICSLR, and label Mandarin characters, syllables, and TIF. We demonstrate the effectiveness of the proposed approach compared to its counterparts through extensive experiments on Grid, ICSLR, and CMLR datasets.
One-Pot Synthesis of Pyrrolo[1,2-a]quinoxaline Derivatives via a Copper-Catalyzed Aerobic Oxidative Domino Reaction. -The title reaction is achieved starting from 1-(2-halophenyl)-1H-pyrroles and -amino acids which may be endowed with various substituents. Iodo-substituted substrates provide the products in higher yields than the corresponding bromo-substituted counterparts. UV-Vis data of some products are examined [cf. (XII)]. -(LIU, H.; DUAN, T.; ZHANG, Z.; XIE, C.; MA*, C.; Org. Lett. 17 (2015) 12, 2932-2935, http://dx.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.