In this work, we propose and study a framework of generalized proximal point algorithms associated with a maximally monotone operator. We indicate sufficient conditions on the regularization and ...relaxation parameters of generalized proximal point algorithms for the equivalence of the boundedness of the sequence of iterations generated by this algorithm and the non-emptiness of the zero set of the maximally monotone operator, and for the weak and strong convergence of the algorithm. Our results cover or improve many results on generalized proximal point algorithms in our references. Improvements of our results are illustrated by comparing our results with related known ones.
A new metal‐free oxidative radical 2+2+1 carbocyclization of benzene‐linked 1,n‐enynes with two C(sp3)H bonds adjacent to the same heteroatom is described. This method achieves two C(sp3)H ...oxidative functionalizations and an annulation, thus providing efficient and general access to a variety of fused five‐membered carbocyclic hydrocarbons.
An oxidative functionalization of two C(sp3)H bonds adjacent to a same heteroatom for the 2+2+1 carbocyclization with benzene‐linked 1,n‐enynes is presented. This method successfully proceeds using a radical mechanism and provides straightforward access to a variety of fused five‐membered carbocyclic hydrocarbons. TBPB=tert‐butyl perbenzoate.
A mild and general visible light photoredox catalysis-induced intermolecular three-component alkene 1,2-diarylation involving aryl C(sp2)-H functionalization is described. The key to controlling the ...chemoselectivity toward alkene 1,2-diarylation is the employment of a 2,2'-bipyridine base, thus allowing the formation of two new C(sp3)-C(sp2) bonds via aryl radical formation from aryldiazonium salts, addition across the Cdouble bond, length as m-dashC bonds, and aryl C(sp2)-H functionalization cascades.
MXenes, as a novel kind of two-dimensional (2D) materials, were first discovered by Gogotsi
et al.
in 2011. Owing to their multifarious chemical compositions and outstanding physicochemical ...properties, the novel types of 2D materials have attracted intensive research interest for potential applications in various fields such as energy storage and conversion, environmental remediation, catalysis, and biomedicine. Although many achievements have been made in recent years, there still remains a lack of reviews to summarize these recent advances of MXenes, especially in biomedical fields. Understanding the current status of surface modification, biomedical applications and toxicity of MXenes and related materials will give some inspiration to the development of novel methods for the preparation of multifunctional MXene-based materials and promote the practical biomedical applications of MXenes and related materials. In this review, we present the recent developments in the surface modification of MXenes and the biomedical applications of MXene-based materials. In the first section, some typical surface modification strategies were introduced and the related issues were also discussed. Then, the potential biomedical applications (such as biosensor, biological imaging, photothermal therapy, drug delivery, theranostic nanoplatforms, and antibacterial agents) of MXenes and related materials were summarized and highlighted in the following sections. In the last section, the toxicity and biocompatibility of MXenes
in vitro
were mentioned. Finally, the development, future directions and challenges about the surface modification of MXene-based materials for biomedical applications were discussed. We believe that this review article will attract great interest from the scientists in materials, chemistry, biomedicine and related fields and promote the development of MXenes and related materials for biomedical applications.
MXenes, as a novel kind of two-dimensional (2D) materials, were first discovered by Gogotsi
et al.
in 2011.
AbstractThis paper proposes a uniform design (UD)-based Gaussian process regression (GPR) method for rapid damage assessment and fragility estimates of bridges. The core idea of the proposed method ...is that the GPR model was adopted to establish the relationship between the seismic damage and various parameters including bridge properties and earthquake attributes, and the UD method was implemented to enhance the training data set to improve the performance of the GPR model. An efficient method is proposed to improve the use of the UD method over empirical data to search the optimal training data set. Various empirical samples of damaged bridges from the 2008 Wenchuan earthquake in China were collected to validate the predictive ability of the proposed UD-GPR method. The ability and stability of the UD-GPR method for damage classification were evaluated using samples from other earthquakes that were not included in the training data set. The influence of different kernels for the GPR model, different sample sizes, and different discrepancies of training data sets on the predictions of the UD-GPR model was investigated. The empirical fragility curves for different bridge types were derived based on the results of damage classification. The efficiency and accuracy of the UD-GPR method for generating the fragility curves were validated by the actual fragility curves developed by the existing references. The effects of sample size and discrepancy on the median fragility and fragility dispersion were discussed. It can be concluded that the UD-GPR model is efficient and accurate for damage assessment and fragility analysis of bridges even when the training data set has a small number of samples, which can be helpful and beneficial for rapid postearthquake assessment of bridges.
The first iron‐catalyzed 1,2‐difunctionalization of styrenes and conjugated alkenes with silanes and either N or C, using an oxidative radical strategy, is described. Employing FeCl2 and ...di‐tert‐butyl peroxide allows divergent alkene 1,2‐difunctionalizations, including 1,2‐aminosilylation, 1,2‐arylsilylation, and 1,2‐alkylsilylation, which rely on a wide range of nucleophiles, namely, amines, amides, indoles, pyrroles, and 1,3‐dicarbonyls, thus providing a powerful platform for producing diverse silicon‐containing alkanes.
Iron clad: By employing FeCl2 and di‐tert‐butyl peroxide (DTBP), divergent alkene 1,2‐difunctionalization reactions, including 1,2‐aminosilylation, 1,2‐arylsilylation, and 1,2‐alkylsilylation, are achieved by using different nucleophiles. The method provides straightforward and practical access to 1‐amino‐2‐silylalkanes and other functionalized silicon‐containing alkanes with broad substrate scope and high selectivity.
Owing to their easy availability and cheapness, simple alkyl chlorides are good raw materials for introducing complex polychlorinated groups. Polychlorinated hydrocarbons units, such as di‐ or ...trichloromethyl groups, not only widely found in pesticide and bioactive molecule, but also can be as a precursor to converted into different functional groups such as −COOH, −CHO and −CO. The direct polychloroalkylation reaction by using simple alkyl chlrides has been considered to be an important tool for synthesizing complex polychlorinated compounds. This review summarizes recent developments, especially free radical strategies, in the polychloroalkylation of different substrates (such as 2‐acylpyridines, benzyl tertiary amines, alkenes, imine and 1,n‐enynes). We hope that this review provides a new perspective on this field and also provides a reference to develop environmentally friendly and sustainable methods.
We have disclosed an alkenes dicarbofunctionalization method to introduce alkyl and electron‐rich aryl across the C=C bond of styrenes under copper catalyst and oxidative conditions, leading to ...construct C(sp3)‐C(sp2)/C(sp3)‐C(sp3) bonds via dual C−H functionalization. This method realizes the synthesis of 1,1‐diarylalkanes, which are very important skeleton in natural products and drug molecules, through the grafting of electron‐rich aromatics, including indoles, pyrroles, trisubstituted aromatic.
The In(OTf)
-promoted three-component photoredox alkylarylation of styrenes with alkyl NHP esters and arenes to access alkylated arene derivatives through C-C bond cleavage and C-H functionalization ...is reported. By utilizing visible-light photoredox catalysis, alkyl N-hydroxyphthalimide esters serving as alkyl carbon-centered radicals and a wide range of arenes (e.g., indoles, pyrrole, and electron-rich arenes) as nucleophiles were used to enable the introduction of various alkyl groups and aryl groups across the Cdouble bond, length as m-dashC bonds with excellent selectivity and functional group tolerance.
A new iron‐facilitated silver‐mediated radical 1,2‐alkylarylation of styrenes with α‐carbonyl alkyl bromides and indoles is described, and two new C−C bonds were generated in a single step through a ...sequence of intermolecular C(sp3)−Br functionalization and C(sp2)−H functionalization across the alkenes. This method provides an efficient access to alkylated indoles with broad substrate scope and excellent selectivity.
Bridging alkene: An intermolecular arene C(sp2)−H functionalization strategy is established for the radical 1,2‐alkylarylation of styrenes with α‐carbonyl alkyl bromides and indoles using iron as the catalyst and silver as the promotor. This method enables the formation of two C−C bonds in a single reaction. acac=acetylacetonate.
![Metal-Free Radical [2+2+1] ...](http://api.summon.serialssolutions.com/2.0.0/image/issn/XR4PS5YY4K/1433-7851/small "Metal-Free Radical [2+2+1] Carbocyclization of Benzene-Linked 1,n-Enynes: Dual C(sp3)H Functionalization Adjacent to a Heteroatom")
