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A highly diastereoselective synthesis of a previously unknown type of aminobenzothiazol derivatives of high pharmaceutical potential is given.

The synthesis of a novel type of fluorinated sulfonamides with high pharmaceutical potential can be scaled up.

A metal-free cyclization reaction of 2-isocyanobiphenyls with amide derivatives by using tert-butyl peroxybenzoate (TBPB) as oxidant was developed, which provided an access to pharmacologically interesting 6-amidophenanthridine compounds. The reactions proceeded through a sequence of functionalization of the C(sp(3))-H bond adjacent to the nitrogen atom and intramolecular radical aromatic cyclization with good chemistry yields.

Enolates of indolin-2-ones react cleanly with the chiral imine (II) to afford adducts (III) and (V) in good diastereoselectivity.

Accurate short-term traffic volume prediction is essential for the realization of sustainable transportation as providing traffic information is widely known as an effective way to alleviate congestion. In practice, short-term traffic predictions require a relatively low computation cost to perform calculations in a timely manner and should be tolerant to noise. Traffic measurements of variable quality also arise from sensor failures and missing data. There is no optimal prediction model so far fulfilling these challenges. This paper proposes a so-called absorbing Markov chain (AMC) model that utilizes historical traffic database in a single time series to carry out predictions. This model can predict the short-term traffic volume of road links and determine the rate in which traffic eases once congestion has occurred. This paper uses two sets of measured traffic volume data collected from the city of Enschede, Netherlands, for the training and testing of the model, respectively. The main advantag...

Herein is reported a study of asymmetric decarboxylative Mannich addition reactions between (Ss)-N-t-butylsulfinyl-3,3,3-trifluoroacetaldimine and Schiff bases derived from various aldehydes and lithium 2,2-diphenylglycinate. These reactions proceed with excellent diastereoselectivities and good chemical yields, providing a practical method for preparation of trifluoromethyl-containing vicinal diamines. The procedures can be conducted under convenient conditions, rendering this approach of high synthetic value.

CF3-containing chiral imines readily react with α,α-difluoroenolates affording a novel type of β-keto-amino compounds featuring the R-CO-CF2-CH(NH2)-CF3 moiety. The reactions feature exceptional generality allowing preparation of various aromatic, hetero-aromatic and aliphatic derivatives in high yields and diastereoselectivity. The products are configurationally stable and can be transformed to more functionalized complex compounds.

Here we describe the first attempts to scale up five addition reactions between (SS)-N-tert-butanesulfinyl-(3,3,3)-trifluoroacetaldimine 6 with C-nucleophiles derived from ketones (two examples), glycine Schiff base and heterocycles (two examples). In all cases studied, the observed stereochemical outcome of the scaled up (5.0–25.0 mmol) reactions was lower as compared with the original 0.5 mmol scale. However, the observed worsening of yields and diastereoselectivity was not identical and depended on the reaction conditions and reaction mechanisms. In general, scaling up of the reactions conducted at ambient temperatures presented no problems while the low-temperature (−78 °C) processes would require special equipment to provide strict maintenance of the reaction temperature to obtain the desirable outcome. Importantly, using procedures described here, series of biologically relevant compounds containing 2,2,2-trifluoro-1-(amino)ethyl [CF3 CH(NH2)-] pharmacophore unit can be prepared in enantiomerically pure form on up to 5 g scale, allowing their systematic biological studies.

The main feature of the synthesis of unexpected bis(benzothiazolyl)ethanes is the unusual role of CF3-imine, which serves as a precursor to the bridging ethylene moiety.

Compound (IIIa) can be further transformed to the corresponding β-amino alcohol by stereoselective reduction of its ketone moiety.

To introduce a new external fixation device for the management of syndactyly in children. To evaluate its preliminary clinical result. From January 2011 to June 2012, 12 cases with cutaneous syndactyly of the middle/ring finger were managed with a new external fixator designed by our department. There were eight cases on the right side and four on the left side. The web space and soft tissue were stretched gradually using the new device. A Z-plasty of syndactylies was performed when the web space has reached the width that we required. The results were evaluated according to the clinical appearance and function of the fingers. Twelve cases had been followed up, with an average time of 16 months (range, 12-27 months). The web space and soft tissue in all the cases were stretched successfully using the new device. Skin grafting was not necessary in the reconstruction of syndactyly. In the last follow-up, the Vancouver Score averaged 0.6 (range, 0-2). Three cases had grade 1 web creep, whereas the other nine cases had grade 0 web creep. The total active motion averaged 130.4° for all affected fingers: 130.8° for the middle and 130.0° for the ring finger. Stiffness in the PIP joint preoperatively in two cases did not improve postoperatively. In 12 affected middle fingers, three cases had a supination deformity averaging 10.6° (range, 5°-15°) and one case had a pronation deformity of 5°. In 12 affected ring fingers, one case had a supination deformity of 18° and two cases had a pronation deformity averaging 7.5° (range, 5°-10°). The middle finger was not pronated in any patient. Among all the ring fingers, two had radial deviation of 8°and 25° and 1 had ulnar deviation of 10°. The surgeon-provided visual analog scale score for esthetics averaged 1.8 (range, 0-5). The parent-provided visual analog scale score was 2.7 (range, 1-5) for pain, 1.3 (range, 0-5) for appearance, and 1.3 (range, 0-5) for function. Displacement of the nail bed during distraction was found in two cases, which was resolved by the Winograd technique in the second surgery of syndactyly release. The clinical appearance and function were excellent. When we use the new external fixation device in the management of syndactyly, we can achieve a satisfactory outcome with little scar of the fingers. There was no need for skin grafting. However, the long-term result should be studied further.

We demonstrate that reactions between various 1-indanones and (SS)-N-tert-butanesulfinyl-(3,3,3)-trifluoroacetaldimine, conducted in the presence of catalytic amounts of LDA, occur with virtually complete stereochemical outcome, offering reliable and generalized access to biologically relevant β-trifluoromethyl-β-amino indanone derivatives. The products can be isolated in diastereomerically pure form simply by washing the crude reaction mixture with hexanes, underscoring practicality of the present method.

Efficient asymmetric Mannich addition reactions between α,β-unsaturated ketone derived enolates and N -phosphonyl imines were reported. These reactions could proceed smoothly for a variety of imine substrates with good (up to 96%) chemical yields and excellent diastereoselectivities (up to 98:2 dr). The method reported in this work provides an easy access to chiral β′-amino-α,β-enones.

The asymmetric Mannich-type addition between C5-lithiated heterocycles (I) and enantiopure aldimine (II) is described.

We have demonstrated that 3,3,3-trifluoroacetaldimine (S)-1 easily reacts with indole derivatives under Friedel–Crafts reactions to provide reliable and generalized access to biologically interesting compounds containing the CF3CH(NH2)– pharmacophoric group. The reactions proceed with high rates and generally excellent yields (>90%) and stereochemical outcomes (99:1 dr).

Here we report that, unlike other ketones, 1-indanone and acetophenone derived enolates undergo Mannich-type addition reactions with N-tert-butanesulfinyl ketimines with excellent yields (up to 98%) and diastereoselectivity (>99/1). The resulting compounds represent a new type of biologically relevant β-aminoketone derivative bearing quaternary stereogenic carbon, which could be further converted into the corresponding β-amino ketones and β-amino alcohols, possessing three consecutive stereogenic centres.

In the title reaction, the N-tert-butylsulfinyl group serves not only as an efficient chiral auxiliary, but also as an amine protecting group.

This study describes asymmetric Mannich-type additions between C-5 lithiated thiazolo[3,2-b][1,2,4]triazoles and enantiomerically pure (SS)-N-tert-butanesulfinyl-(3,3,3)-trifluoroacetaldimine. Under the optimized conditions, these reactions proceed with good (up to 78%) chemical yields and virtually complete (98 : 2 to >99 : 1 dr) diastereoselectivity. The same stereochemical outcome was obtained using 1.05 g scale of the starting (3,3,3)-trifluoroacetaldimine. The method developed in this work provides concise and generalized access to thiazolo[3,2-b][1,2,4]triazoles containing a chiral (trifluoro)ethylamine group.

A series of chiral N-phosphonyl protected α-alkenyl homoallylic primary amines were synthesized by asymmetric addition of allylmagnesium bromide Grignard reagent towards chiral α,β-unsaturated imines. Only 1,2-adduct was obtained for all the imines with good yields and excellent diastereoselectivities. The chiral auxiliary could be easily removed under simple conditions, giving free multiple functionalized primary amines.

A facile and green aminochlorination of β-nitrostyrenes has been developed by using t-butyl N,N-dichlorocarbamate (BocNCl2) as a nitrogen/chlorine source in water at room temperature, which tolerated a wide range of substrates and resulted in the highest efficiency so far.

Relay Based Cellular Networks (RBCNs) are a key development in cellular networking technology. However, because of ever increasing demand and base station failure, RBCNs still suffer from user congestion and low resilience problems. This paper proposes two competing solutions: dynamic frequency allocation and antenna tilting to those problems. Firstly a new dynamic fractional frequency allocation algorithm and a heuristic antenna tilting algorithm are designed. The comparative benefits of each algorithm are investigated. Secondly, the additional benefits of applying the two algorithms sequentially or iteratively are evaluated. The benefits of iteratively integrating the two algorithms are more interesting. Such integration solution allows the two algorithms to be applied cooperatively. The evaluations are based on high demand scenarios and base station failure scenarios. The results show that for the high demand scenarios the new dynamic fractional frequency allocation algorithm is very powerful, and the advantage of antenna tilting is not large though present. However, for the BS failure case there is a marked additional benefit in antenna tilting. The integrated solution achieves significantly more benefit than simple sequential application of the two algorithms.

Tetrabenzylhafnium has been explored as a new organometallic reagent for the imine addition reaction. This reagent tolerates a wide scope of imines, affording α-branched amines in excellent yields without the use of any additive or catalyst. This new reagent shows higher efficiency than that observed for classic Grignard and organolithium reagents.

Under optimized conditions, the reaction provides the regioisomers (III) as single products.

The reaction tolerates a wide scope of substrates and gives the dichlorinated products at room temperature in short reaction times.

Cellular networks and Wi-Fi provide range of wireless communication services. They are the practical wireless technologies for domestic and business wireless users currently. However, base station (BS)/access point (AP) may fail in disasters. This failure problem may cause part of users not able to communicate. To solve this problem, one proposed solution is to let users in failure caused coverage hole self-organize to communicate to each other or to functional BS/AP. Delay Tolerate Networking (DTN) is one of such user self-organization technologies. This paper designs and evaluates geographic binary spray and wait routing algorithm (G-BSW) in DTN to let users find routes to close BSs/APs. Meanwhile, BS/AP load balance can be guaranteed. G-BSW is a cooperative algorithm. It controls BSs/APs to broadcast metadata to users to let them find appropriate BS/AP. The metadata contains geographic and related routing information. Through simulation in an open source DTN simulator (ONE simulator), G-BSW is validated to improve message delivery rate, and BS/AP load balance.

Title addition reaction proceeds with good yields and moderate to excellent diastereoselectivities, even on large scale preparation.

Cellular networks provide a range of communication services and are the principal wireless technology for domestic and business users. However, in cellular networks, an accident or a storm or a malicious action may cause a base station to fail and so be unable to provide radio coverage to sections of users. Such base station failures also might result in user congestion to nearby operational base stations. Delay Tolerate Network (DTN) is used here to mitigate these problems. DTN enables user devices to self-organize to connect to functional base stations or other users through multiple hops. This paper augments DTN routing using geographic routing and Ant Colony Optimization (ACO) methods to enhance user to base station connection and network load balancing. Three DTN routing protocols: Epidemic, Binary Spray and Wait, and PRoPHET are considered in this paper. Compared to the geographic method described, the ACO does not require users and base stations to provide their geographic location, which is more appropriate to the context in which such an approach might be applied.

An efficient one-pot system has been developed for the synthesis of cyano aziridine by using α,β-unsaturated nitriles as the alkene substrates and N,N-dichloro-p-toluenesulfonamide (4-TsNCl(2) ) as the nitrogen source. A good scope of alkene substrates was achieved for this reaction. The one-pot reaction, via aminohalogenation and intramolecular S(N) 2 substitution, was very convenient to carry out at room temperature without the protection of inert gases. Modest to good yields and excellent have been obtained. This method provides an easy route to the cyano aziridine. The structure of the resulting products has been unambiguously confirmed by X-ray structural analysis.

This paper illustrates an approach to improving the user perceived QoS in heterogeneous networks through the use of a two layered optimization. The top layer views the problem of prediction of the network that would be chosen by a user where the criteria are offered bit rate, price, mobility support and reputation. At the second level, conditional on the strategies chosen by the users, the network operator hypothetically, reconfigures the network, subject to the network constraints of bandwidth and acceptable SNR and optimizes the network coverage to support users who would otherwise not be serviced adequately. This forms an iterative cycle until a solution that optimizes the user satisfaction subject to the adjustments that the network operator can make to mitigate the binding constraints, is found. The process is illustrated through a simple example using a Wi-Fi and a WiMAX network.

An efficient direct aldol reaction has been developed for the synthesis of chiral beta-hydroxy ketone using a combination of C(1)-symmetric chiral prolinamides based on o-phenylenediamine and zinc triflate as catalyst. The reaction was convenient to carry out in aqueous media with up to 98% chemical yields and up to 94% ee values. The current strategy can be regarded as the analogue of aldolase type II, which suggests a new pathway for the designing of new organocatalysts.

Relay based cellular network (RBCN) is a kind of hybrid cellular network working under OFDMA technology. It is a promising network to support high transmitting data-rate, throughput, capacity, flexibility and resource efficiency. Normally QoS offered to mobile user (MS) is improved in RBCN by using relay station (RS) to enhance Base station (BS) radio coverage. But in reality, QoS is affected by service congestion problem caused by MS un-balance distribution and limited capacity and mobility of BS and RS. So this paper introduces an algorithm to cooperatively control the pilot power at the BSs and RSs of a RBCN for geography load balance to release this service congestion problem. The performance of the algorithm is evaluated using a WiMAX simulator and the results are compared to a state of art greedy algorithm in literature and the conventional RBCN.

Asymmetric Mannich reactions of imidazo[2,1-b]thiazole-derived nucleophiles with (SS)-N-tert-butanesulfinyl (3,3,3)-trifluoroacetaldimine were found to proceed with reasonably good yields (55%–79%) and exceptionally high stereoselectivity (>99 : 1 dr). This method presents a general approach for the preparation of a new type of biologically relevant compounds containing pharmacophoric imidazo[2,1-b]thiazole and (trifluoro)ethylamine groups.

A highly efficient and facile aminohalogenation of β-nitrostyrenes with t-butyl N,N-dichlorocarbamate (BocNCl2) as nitrogen/halogen source is reported, which tolerated a wide scope of substrates and could be completed within 20 min at room temperature with excellent chemical yields.

An efficient method for the asymmetric synthesis of β-trifluoromethylated β-amino ketones via addition of ketone-derivative enolates to trifluoromethylated sulfinylimine has been developed, with good chemical yields and excellent diastereoselectivities. This practical method was also proved to be suitable for large-scale preparation.