Copper-Catalyzed Asymmetric Arylation of α-Substituted Cyanoacetates Enabled by Chiral Amide Ligands.

The (S)-nobin-embodied picolinamide and L-hydroxyproline-derived amide are effective ligands for Cu-catalyzed enantioselective coupling reaction of (hetero)aryl iodides with α-alkyl substituted cyanoacetates. This arylation reaction gave α-(heteroaryl)-α-alkyl cyanoacetates in good to excellent enantioselectivities (up to 95 % ee). A variety of functionalized (hetero)aryl and alkyl groups could be introduced to the quaternary center and therefore provided a valuable tool for preparing enantioenriched compounds with an all-carbon quaternary center tethered with convertible functional groups. The size of both α-alkyl and ester groups was proven as the key factor for asymmetric induction.

Evaluation Algorithm for the Effectiveness of Stroke Rehabilitation Treatment Using Cross-Modal Deep Learning.

It is important to study the evaluation algorithm for the stroke rehabilitation treatment effect to make accurate evaluation and optimize the stroke disease treatment plan according to the evaluation results. To address the problems of poor restoration effect of positron emission tomography (PET) image and recognition restoration effect of evaluation data and so on. In the paper, we propose a stroke rehabilitation treatment effect evaluation algorithm based on cross-modal deep learning. Magnetic resonance images (MRI) and PET of stroke patients were collected as evaluation data to construct a multimodal evaluation dataset, and the data were divided into positive samples and negative samples. According to the mapping relationship between MRI and PET, three-dimensional cyclic adversarial is used to generate the neural network model to recover the missing PET data. Using the cross-modal depth learning network model, the RGB image, depth image, gray image, and normal images of MRI and PET are taken as the feature images and the multifeature fusion method is used to fuse the feature images, output the recognition results of MRI and PET, and evaluate the effect of stroke rehabilitation treatment according to the recognition results. The results show that the proposed algorithm can accurately restore PET images, the evaluation data recognition effect is good, and the evaluation data recognition accuracy is higher than 95%. The evaluation accuracy of stroke rehabilitation treatment effect is high, the evaluation time varies between 0.56 s and 0.91 s, and the practical application effect is good.

Transition Metal-Free Cross-Dehydrogenative Coupling Reaction of Coumarins with Acetonitrile or Acetone.

A transition metal-free cross-dehydrogenative coupling of coumarins with acetonitrile or acetone has been established. A series of coumarins were subjected to reaction with acetonitrile or acetone in the presence of tert-butyl benzoperoxoate and potassium fluoride for direct synthesis of 3-cyanomethyl (or acetomethyl) coumarins. The method exhibits good functional group tolerance, and desired products were obtained in moderate to good yields. Meanwhile, a radical pathway was proposed to describe the cross-dehydrogenative coupling of coumarins with acetonitrile.

Three-component difunctionalization of alkenes leading to ß-acetamido sulfides and ß-acetoxy sulfides.

A novel method for the synthesis of ß-acetamido sulfides via NBS-mediated aminosulfenylation of alkenes with thiophenols and nitriles under metal-free conditions has been described. And ß-acetamido sulfides were also synthesized with 1-(arylthio)pyrrolidine-2,5-diones as substrates and HBr as an additive. On the other hand, iodine-catalyzed 1,2-acetoxysulfenylation of alkenes by using (diacetoxyiodo)benzene as an oxygen source to synthesise various ß-acetoxy sulfides was described as well.

Copper-Mediated Oxidative Functionalization of C(sp3)-H Bonds with Isoquinolines: Two-Step Synthesis of 5-Oxaprotoberberinones.

A copper-mediated oxidative functionalization of C(sp3)-H bonds with isoquinolines via a radical process without ligands was achieved. The present system exhibits a novel pathway for the preparation of N-alkyl (benzyl) isoquinolin-1(2H)-ones in moderate to high yields. In addition, this procedure provides a simple method to afford 5-oxaprotoberberinones and their derivatives in two steps.

Three-component oxysulfenylation reaction: two simple and convenient approaches to ß-alkoxy sulfides.

An unprecedented method for the synthesis of ß-alkoxy sulfides via a NaI/HBr-mediated three-component oxysulfenylation reaction of alkenes with arylsulfinic acids and alcohols is reported. Furthermore, I2-promoted oxysulfenylation of alkenes using sodium arylsulfinates instead of arylsulfinic acids to synthesise various ß-alkoxy sulfides is also described.