Copper(I)-Catalyzed Asymmetric Hydrophosphination of 3,3-Disubstituted Cyclopropenes.

Herein, a copper(I)-catalyzed asymmetric hydrophosphination of 3,3-disubstituted cyclopropenes is reported. It provides a series of phosphine derivatives in high to excellent diastereo- and enantioselectivities. The methodology enjoys broad substrate scope on both 3,3-disubstituted cyclopropenes and diarylphosphines. The high stereoselectivity is attributed to both the high stability of the Cu(I)-(R,R)-QUINOXP* complex in the presence of stoichiometric HPPh2 and the produced phosphines, and the high-performance asymmetric induction of the Cu(I)-(R,R)-QUINOXP* complex. Finally, the method is used for the synthesis of new chiral phosphine-olefin compounds built on a cyclopropane skeleton, one of which serves as a wonderful ligand in Rh-catalyzed asymmetric conjugate addition of phenylboronic acid to various α,ß-unsaturated compounds.

Properties of new exotic traditional Chinese medicinal Vernonia amygdalina leaves:a literature research / 中国中药杂志

The leaves of Vernonia amygdalina Delile of the family Asteraceae(also known as "bitter leaf"), rich in biological activities, are used as both medicine and food for a long time in West tropical Africa. They have been introduced into Southeast Asia and Fujian and Guangdong provinces of China in recent years. However, little is known about the properties of the plant in traditional Chinese medicine(TCM), which limits its combination with other Chinese medicinal herbs. In this study, 473 articles on V. amygdalina leaves were selected from PubMed, Web of Science, CNKI, Wanfang Data and VIP to summarize their components, pharmacological effects and clinical research. V. amygdalina leaves presented anti-microbial, hypoglycemic, anti-hypertensive, lipid-lowering, anti-tumor, anti-inflammatory, antioxidant, and other pharmacological effects. On the basis of the theory of TCM properties, the leaves were inferred to be cold in property and bitter and sweet in flavor, acting on spleen, liver, stomach and large intestine and with the functions of clearing heat, drying dampness, purging fire, removing toxin, killing insects and preventing attack of malaria. They can be used to treat dampness-heat diarrhea, interior heat and diabetes, malaria, insect accumulation and eczema(5-10 g dry leaves by decoction per day and an appropriate amount of crushed fresh leaves applying to the affected area for external use). Due to the lack of TCM properties, V. amygdalina leaves are rarely used medicinally in China. The determination of medicinal properties of the leaves is conducive to the introduction of new exotic medicinal herbs and the development of new TCM resources, which facilitated further clinical application and research and development of Chinese medicinal herbs.

New model of PIRADS and adjusted prostatespecific antigen density of peripheral zone improves the detection rate of initial prostate biopsy: a diagnostic study / 亚洲男科学杂志(英文版)

This study explored a new model of Prostate Imaging Reporting and Data System (PIRADS) and adjusted prostate-specific antigen density of peripheral zone (aPSADPZ) for predicting the occurrence of prostate cancer (PCa) and clinically significant prostate cancer (csPCa). The demographic and clinical characteristics of 853 patients were recorded. Prostate-specific antigen (PSA), PSA density (PSAD), PSAD of peripheral zone (PSADPZ), aPSADPZ, and peripheral zone volume ratio (PZ-ratio) were calculated and subjected to receiver operating characteristic (ROC) curve analysis. The calibration and discrimination abilities of new nomograms were verified with the calibration curve and area under the ROC curve (AUC). The clinical benefits of these models were evaluated by decision curve analysis and clinical impact curves. The AUCs of PSA, PSAD, PSADPZ, aPSADPZ, and PZ-ratio were 0.669, 0.762, 0.659, 0.812, and 0.748 for PCa diagnosis, while 0.713, 0.788, 0.694, 0.828, and 0.735 for csPCa diagnosis, respectively. All nomograms displayed higher net benefit and better overall calibration than the scenarios for predicting the occurrence of PCa or csPCa. The new model significantly improved the diagnostic accuracy of PCa (0.945 vs 0.830, P < 0.01) and csPCa (0.937 vs 0.845, P < 0.01) compared with the base model. In addition, the number of patients with PCa and csPCa predicted by the new model was in good agreement with the actual number of patients with PCa and csPCa in high-risk threshold. This study demonstrates that aPSADPZ has a higher predictive accuracy for PCa diagnosis than the conventional indicators. Combining aPSADPZ with PIRADS can improve PCa diagnosis and avoid unnecessary biopsies.

Copper(I)-Catalyzed Asymmetric Synthesis of P-Chiral Aminophosphinites.

Herein, a copper(I)-catalyzed reaction of diarylphosphines and O-benzoyl hydroxylamines is developed. In the cases of symmetrical diarylphosphines, a series of aminophosphinites is prepared in high yields. In the cases of unsymmetrical diarylphosphines, an array of P-chiral aminophosphinites is synthesized in high yields with high enantioselectivity by using a copper(I)-(R,RP )-Ph-FOXAP complex as a chiral catalyst. Based on several control experiments and 31 P NMR studies, a two-electron redox mechanism involving the dynamic kinetic asymmetric transformation of unsymmetrical diarylphosphines is proposed for the copper(I)-catalyzed asymmetric reaction. Finally, one representative P-chiral phosphoric amide generated through the oxidation with H2 O2 is transformed to a chiral diarylphosphinate in high yield with retained enantioselectivity, which allows further transformations towards various P-chiral tertiary phosphines.

Copper(I)-Catalyzed Asymmetric Alkylation of Unsymmetrical Secondary Phosphines.

A copper(I)-catalyzed asymmetric alkylation of HPAr1Ar2 with alkyl halides is uncovered, which provides an array of P-stereogenic phosphines in generally high yield and enantioselectivity. The electrophilic alkyl halides enjoy a broad substrate scope, including allyl bromides, propargyl bromide, benzyl bromides, and alkyl iodides. Moreover, 11 unsymmetrical diarylphosphines (HPAr1Ar2) serve as competent pronucleophiles. The present methodology is also successfully applied to catalytic asymmetric double and triple alkylation, and the corresponding products were obtained in moderate diastereo- and excellent enantioselectivities. Some 31P NMR experiments indicate that bulky HPPhMes exhibits weak competitively coordinating ability to the Cu(I)-bisphosphine complex, and thus the presence of stoichiometric HPAr1Ar2 does not affect the enantioselectivity significantly. Therefore, the high enantioselectivity in this reaction is attributed to the high performance of the unique Cu(I)-(R,RP)-TANIAPHOS complex in asymmetric induction. Finally, one monophosphine and two bisphosphines prepared by the present reaction are employed as efficient chiral ligands to afford three structurally diversified Cu(I) complexes, which demonstrates the synthetic utility of the present methodology.

Rapid Synthesis of Chiral 1,2-Bisphosphine Derivatives through Copper(I)-Catalyzed Asymmetric Conjugate Hydrophosphination.

1,2-Bisphosphines have been identified as one class of important and powerful chiral ligands in asymmetric catalysis with transition metals. Herein, a copper(I)-catalyzed asymmetric hydrophosphination of α,ß-unsaturated phosphine sulfides was developed with the assistance of "soft-soft" interaction between copper(I)-catalyst and the phosphine sulfide moiety, which afforded 1,2-bisphosphine derivatives with diversified electronic nature and steric hindrance in high to excellent yields with high to excellent enantioselectivity. Moreover, the challenging catalytic asymmetric hydrophosphination/protonation reaction was achieved with excellent enantioselectivity. Strikingly, the dynamic kinetic resolution of racemic diarylphosphines was also successfully carried out with high to excellent diastereo- and enantioselectivities. Interestingly, the nucleophilic copper(I)-diphenylphosphide species was characterized by 31 P NMR spectrum and mass spectrum. At last, three products were transformed to chiral 1,2-bisphosphines, which were employed as ligands in Rh-catalyzed asymmetric hydrogenation of α-amino-α,ß-unsaturated ester. The α-amino acid derivative was produced in high enantioselectivity, which demonstrated the utility of the present methodology.

Iridium-catalyzed direct asymmetric vinylogous allylic alkylation.

The catalytic asymmetric vinylogous allylic alkylation of α,ß-unsaturated lactones (including coumarins) was achieved with excellent regio- and enantioselectivity. Transformations of the product were carried out by means of the versatile terminal olefin and lactone moieties. The synthetic application of the present methodology was showcased by the asymmetric synthesis of an advanced synthetic Merck intermediate toward a new drug candidate.