Practical Synthesis of Chiral α-Aminophosphonates with Weak Bonding Organocatalysis at ppm Loading.

α-Aminophosphonic acids as an important class of bioisosteres of α-amino acids demonstrate various biologically important activities. We report here the development of a highly enantioselective isomerization of α-iminophosphonates enabled by an extraordinarily efficient organocatalyst. This organocatalyst afforded a total turnover number (TON) of 20,000-1,000,000 for a wide range of α-alkyl iminophosphonates. Even at a parts-per-million (ppm) loading, this catalyst achieved a complete reaction in greater than 93% enantiomeric excess (ee). Computational studies revealed that this small-molecule catalyst achieved enzyme-like efficiency via a network of weak bonding interactions that effectively preorganized the substrate and catalyst toward a transition-state-like complex. Considering the substrate tolerance, catalytic efficiency, and mechanism, this organocatalyst could be regarded as a small-molecule isomerase.

Deoxygenative Nucleophilic Phosphonation and Electrophilic Alkylation of Secondary Amides: A Facile Access to Quaternary α-Aminophosphonates.

The widespread occurrence and synthetic accessibility of amides render them valuable precursors for the synthesis of diverse nitrogen-containing compounds. Herein, we present a metal-free and streamlined synthetic strategy for the synthesis of quaternary α-aminophosphonates. This approach involves sequential deoxygenative nucleophilic phosphonation and versatile electrophilic alkylation of secondary amides in a one-pot fashion. Notably, this method enables the direct bis-functionalization of secondary amides with both nucleophiles and electrophiles for the first time, with simple derivatization leading to valuable free α-aminophosphonates by hydrolysis. The protocol has the advantages of operational simplicity, broad functional-group compatibility, environmental friendliness, and scalability to multigram quantities.

Effects of continuing nursing care under cognitive behavioral intervention on psychological state and living quality in patients with double J catheter after ureterolithiasis surgery.

OBJECTIVE: The effects of continuing nursing care under cognitive behavioral intervention on the psychological state and living quality of patients with double J catheter after ureterolithiasis surgery were analyzed in this research. METHODS: The research subjects in this study were 142 patients who were discharged from our hospital with a double J tube after ureterolithiasis surgeries from June 2019 to June 2020. According to the patient care plan, the subjects were divided into the control group (n=71) and the observation group (n=71) and respectively treated with routine basic nursing measures and continuing nursing care under cognitive-behavior intervention. Subsequently, the psychological state, living quality and the complications that occurred were compared between the two groups. RESULTS: The depression and anxiety scores of the two groups after 4 weeks of intervention, comparing to thoes before intervention, were seen with remarkably decreased significance (P<0.05). The scores of living quality and self-care quality of patients in the observation group were obviously higher than those in the control group (P<0.05). In addition, the incidence of complications in the observation group was critically lower than that in control group (P<0.05). CONCLUSION: Continuous nursing care under cognitive behavioral intervention can substantially improve the psychological state, living quality and self-care ability of patients with double J tube after ureterolithiasis surgery, and reduce the incidence of complications, which is worthy of clinic promotion.

Catalytic asymmetric hydrogenation of (Z)-α-dehydroamido boronate esters: direct route to alkyl-substituted α-amidoboronic esters.

The direct catalytic asymmetric hydrogenation of (Z)-α-dehydroamino boronate esters was realized. Using this approach, a class of therapeutically relevant alkyl-substituted α-amidoboronic esters was easily synthesized in high yields with generally excellent enantioselectivities (up to 99% yield and 99% ee). The utility of the products has been demonstrated by transformation to their corresponding boronic acid derivatives by a Pd-catalyzed borylation reaction and an efficient synthesis of a potential intermediate of bortezomib. The clean, atom-economic and environment friendly nature of this catalytic asymmetric hydrogenation process would make this approach a new alternative for the production of alkyl-substituted α-amidoboronic esters of great potential in the area of organic synthesis and medicinal chemistry.

Dynamic Kinetic Asymmetric Reductive Amination: Synthesis of Chiral Primary ß-Amino Lactams.

A highly efficient ruthenium-catalyzed asymmetric reductive amination (ARA) of racemic ß-keto lactams with molecular hydrogen and ammonium salts is disclosed for the synthesis of enantiomerically pure primary amino lactams through dynamic kinetic resolution (DKR). By this approach, a range of syn primary ß-amino lactams were obtained in high yields with high chemo-, enantio-, and diastereoselectivity (up to 98 % yield, 99 % ee, >20:1 d.r., syn products). The utility of the products has been demonstrated by rapid access to a key synthetic intermediate towards biologically active drug molecules. Meanwhile, mechanistic studies and control experiments indicate that the reaction may proceed through the hydrogenation of an iminium intermediate.

Enantioselective and Diastereoselective Ir-Catalyzed Hydrogenation of α-Substituted ß-Ketoesters via Dynamic Kinetic Resolution.

An iridium/f-amphol catalytic system for the enantioselective hydrogenation of α-substituted ß-ketoesters via dynamic kinetic resolution is reported. The desired anti products were obtained in high yields (up to 98%) with good diastereoselectivity (up to 96:4 diastereometic ratio (dr)) and excellent enantioselectivity (up to >99% enantiomeric excess (ee)). A catalytic model is proposed to explain the stereoselectivity.

[Endemic Situation and Control of Malaria in Baoying County of Jiangsu Province from 2005 to 2014].

Malaria information was collected through online systems in Baoying County from 2005 to 2014 and descriptive analysis was performed on the data. A total of 175 cases of malaria were reported in the years, with no report of death. During 2005-2008, vivax malaria cases constituted 86.4%（19/22） of all cases reported, and all infected locally with diease onset mainly occurred from May to November. During 2009-2014, falciparum malaria cases constituted 82.4%（126/153）, and all imported cases, which showed a trend of increase, from one case in 2007 to 22 in 2009. All the cases reported during 2010-2014 were imported cases. As to malaria control, there was an overall regular treatment rate of 100%, 195 patients had radical cure during the resting stage, and blood test was conducted in 52 827 fevered patients, resulting in a positive rate of 0.3%（149/52 827）. Although no local malaria cases were reported since 2010, the imported malaria is still an important issue.

[Discussion on strategy of imported falciparum malaria control in Baoying County, 2007 -2009].

The analysis on control of imported falciparum malaria in Baoying County from 2007 to 2009 showed that all the 25 cases occured were cured. It suggested that the prevention and control strategy and measures on imported falciparum malaria in local areas were effective.

[Surveillance of Oncomelania hupensis snails in Baoying and Gaoyou sections of Li Canal in east route of South-to-North Water Diversion Project].

OBJECTIVE: To understand the distribution and diffusion of Oncomelania hupensis snails in the Baoying and Gaoyou sections of the Li Canal in the east route of the South-to-North Water Diversion Project. METHODS: The retrospective survey method was used to investigate the distribution and diffusion of snails in the Baoying and Gaoyou sections of the Li Canal, the conventional survey and the methods of salvage of water and attracting snails were used to detect the distribution of snails in river banks and water. RESULTS: The earliest findings of snails in the Gaoyou section of the Li Canal was in 1955, the northernmost distribution of snails was Dilong ferry at the west dam and east slope of the Li Canal. The dynamic surveillance in the Gaoyou section of the Li Canal from 2001 to 2010 showed that the snail status was of low density and low fluctuation of area, and the distribution range was 119 degrees 24' 36" -119 degrees 25' 34", 32 degrees 48' 30" -32 degrees 54' 05". From 2006 to 2010, the snails were not found by the methods of salvage of water and attracting snails in the surveillance in the Baoying and Gaoyou sections of the Li Canal. CONCLUSIONS: So far, there is no evidence showing that the snails spread to northward in the Li Canal, however, it is still necessary to carry out the surveillance of snails and schistosomiasis in the east route of the South-to-North Water Diversion Project.

[Determination of soluble organic fraction in diesel exhaust particulates by gas chromatography/mass spectrometry].

The soluble organic fractions (SOF) in diesel exhaust particulates have been extracted with ultrasonic separator and analyzed by gas chromatography/mass spectrometry (GC/ MS). The GC/MS conditions were as follows: an HP SE-50 capillary column (30 m x 0.2 mm i. d. x 0.2 microm); temperature programming started at 100 degrees C, holding for 2.0 min, then increased to 160 degrees C at a rate of 4.0 degrees C /min, then to 250 degrees C at 8 degrees C/min, finally, kept at 250 degrees C for 31.75 min; boiling chamber temperature 260 degrees C; helium gas as carrier; chapiter pressure 45 kPa; sample size 1 microL; electron impact energy of mass spectrometer 70 eV; multiplier voltage 1 800 V; mass range 300 - 500 u. The results showed that under exhaust temperature, about 80% of SOF in particulates were normal or isomeric alkanes with carbon numbers from 9 to 28. The rest of the fractions of SOF were polycyclic aromatic hydrocarbons (homologs of indene, fluorene, phenanthrene, naphthalene etc.) and other organic substances. It is demonstrated that most of SOF were from unburned diesel and engine oils. The testing conclusion should be useful in designing and evaluating particulate filters.