Synthesis and Modulation of Low-Dimensional Transition Metal Chalcogenide Materials via Atomic Substitution

In recent years,low-dimensional transition metal chalcogenide(TMC)materials have garnered growing research attention due to their superior electronic,optical,and catalytic properties compared to their bulk counterparts.The controllable synthesis and manipulation of these materials are crucial for tailoring their properties and unlocking their full potential in various applications.In this context,the atomic substitution method has emerged as a favorable approach.It involves the replacement of specific atoms within TMC structures with other elements and possesses the capability to regulate the compositions finely,crystal structures,and inherent properties of the resulting materials.In this review,we present a comprehensive overview on various strategies of atomic substitution employed in the synthesis of zero-dimensional,one-dimensional and two-dimensional TMC materials.The effects of substituting elements,substitution ratios,and substitution positions on the structures and morphologies of resulting material are discussed.The enhanced electrocatalytic performance and photovoltaic properties of the obtained materials are also provided,emphasizing the role of atomic substitution in achieving these advancements.Finally,challenges and future prospects in the field of atomic substitution for fabricating low-dimensional TMC materials are summarized.

Transition-Metal-Catalyzed Synthesis of Chiral Allylboronates

Since the pioneering work on Cr(Ⅲ)-catalyzed enantioselective[4+2]/allylboration reported by Hall and co-workers,a variety of catalytic methodologies for the asymmetric allylic borylation reactions have been developed to provide chiral allylboronates bearing a wide range of functional groups.This review article describes recent advances in transition-metal catalyzed preparation of chiral allylboronates,especially on those in the past three years,and with the emphasis on the aspect of asymmetric catalysis.According to the mechanism of achieving the chemo-,regio-,stereo-and enantioselectivities,the discussion is divided in two parts:substrate-controlled and catalyst-controlled synthesis.

Transition metal-catalyzed conversion of aldehydes to ketones

Ketones are one of the most important classes of organic compounds, and widely present in various pharmacological compounds, biologically active molecules and functional materials. Over the past few decades, transition metal-catalyzed conversion of aldehydes has been found to be a powerful method.With the continuous development in recent years, it has become an efficient and uncomplicated strategy for constructing ketones. There are four major mechanisms for transition metal-catalyzed ketone synthesis from aldehyde:(1) carbonyl-Heck reaction, that is 1,2-insertion of organometal species to aldehydic C=O double bond,(2) direct insertion of transition metal catalysts to aldehydic C-H bond,(3) aldehyde as acyl radical,(4) aldehyde as carbon radical acceptor. This article summarizes related reports on the transformations of aldehydes to generate corresponding ketones under different reaction conditions.

Transition Metal Catalyzed Enantioselective Borylative Cyclization Reactions

Due to the significance of corresponding products,enantioselective borylative cyclization reactions have been studied intensively in recent years.Many groups have developed efficient methods to transform unsaturated system into asymmetric cyclic organoboron compounds with the ring-size range from three-membered to six-membered in general.Notably,in some cases,fused rings which contain more than two contiguous chiral centers could be obtained by this kind of strategies.This review summarized and reviewed the recent advances in this field and classified these work according to the species of metal catalysts.

Transition metal-catalyzed decarboxylative cross-coupling reactions

Transition metal-catalyzed decarboxylative cross-coupling reactions have recently emerged as a new and important category of organic transformations that find versatile applications in the construction of carbon-carbon and carbon-heteroatom bonds. The use of relatively cheap and stable carboxylic acids to replace organometallic reagents enables the decarboxylative cross-coupling reactions to proceed with good selectivities and functional group tolerance. In the present review we summarize the various types of decarboxylative cross-coupling reactions catalyzed by different transition metal complexes. The scope and applications of these reactions are described. The challenges and opportunities in the field are discussed.

Recent trends and developments in the asymmetric synthesis of profens

The profens belong to a class of nonsteroidal anti-inflammatory drugs(NSAIDs),which exert significant antiinflammatory,analgesic,antipyretic and other pharmacological effects.A considerable number of catalytic asymmetric strategies for the synthesis of enantioenriched profens have been introduced.Herein are outlined recent trends and developments of promising catalytic enantioselective systems for the generation of profens and their derivatives.According to the reaction type,we divided these transformations into three categories:Transition metal-catalyzed asymmetric hydrogenations,transition metal-catalyzed asymmetric cross-couplings and organocatalytic asymmetric transformations.Overviews of generic reaction mechanisms are presented.Ideally,this tutorial review will motivate further interest in the catalytic asymmetric synthesis of highly enantioenriched profens.

2-(甲氧基亚胺基)苯乙酸的合成研究

研究了2-(甲氧基亚胺基)苯乙酸即苯基MIA的合成,并对该工艺的反应条件进行了筛选和优化。将甲氧基胺基盐酸盐和碳酸钠固体分别加入圆底烧瓶中,溶于干燥的二氯甲烷,0℃下加入苯甲酰甲酸,25℃下反应3h。该工艺方法得到72%左右的收率,且反应条件简单温和,工艺设备成本廉价,实现了操作简单、经济实惠和绿色环保的目的。

氮杂环卡宾与过渡金属协同催化反应研究进展

在有机化学反应中,过渡金属和有机小分子催化剂联合催化反应为构建复杂结构分子提供了强有力的策略。根据催化剂的作用方式以及加料的顺序不同,可分为协同催化、串联/序列催化。随着对氮杂环卡宾催化反应的不断深入研究,氮杂环卡宾与Br?nsted酸/碱,Lewis酸串联/序列催化或协同催化得到了迅速发展,实现了反应选择性、对映选择性及非对映选择性的精准调控。目前,氮杂环卡宾在与钯、钛、铜和钌等过渡金属协同催化反应中取得了重要进展,该类反应可被用于一些手性活性分子、生物医药小分子等骨架的构建,具有潜在的应用价值及发展前景。

无过渡金属催化合成喹唑啉-4(3H)-酮类化合物研究进展

综述了无过渡金属催化的喹唑啉-4(3H)-酮类合成方法新进展,指出虽然喹唑啉-4(3H)-酮类化合物合成已经取得很大进步,但仍需大力开发更加经济、绿色环保的路线,如开发牢固且催化活性高的可循环利用催化剂。

Trisubstituted alkenes featuring aryl groups:stereoselective synthetic strategies and applications

In recent years,the synthesis and application of alkenes have attracted increased attention.Triphenylethenes(TriPEs)have lower molecular torsion than tetraphenylethenes(TPEs),which helps to balance the degree of conjugation and the aggregation-induced emission(AIE)effect.The geometry of double bonds has a significant impact on luminescence.Therefore,it is essential to provide a comprehensive summary of the stereoselective synthetic strategies for trisubstituted alkenes.In this review,common strategies for the stereoselective synthesis of alkenes are described,with an emphasis on the origin of stereoselectivity and the types of substrates.In addition,the AIE properties of TriPE and its applications in optoelectronic devices,stimuli-responsive materials,sensors,and therapies were discussed.

过渡金属催化合成硫醚的研究进展

硫醚基团广泛存在于天然产物和药物中,独特的分子结构使其具有较高的生物活性,常被用于药物、电化学材料和香料香精的合成。过渡金属催化的C—S键偶联反应因具有操作简单、高效廉价、反应条件温和等优点而成为合成硫醚化合物的主要方法之一。本文重点从有机硫源和无机硫源两方面,对近年来过渡金属催化合成硫醚的研究进行了综述。

一系列具有CHA结构的过渡金属取代磷酸铝的合成与表征

自从1982年．美国联合碳化公司开发出一系列磷酸铝微孔化合物（AlPO4-n）以来，人们利用水热、溶剂热以及离子热技术．已经有200余种不同结构类型的磷酸铝开放骨架化合物被合成出来。这类化合物在催化、分离、气体吸附、离子交换等领域有着广泛的应用．此外在传感、发光等方面也有着潜在的应用价值。

Keggin型过渡金属杂多配合物SiW_(11)M^(x-)(M=Mn~Ⅲ、Fe~Ⅲ、Co~Ⅲ)的稳定性、磁性及催化性能研究

合成了三价态过渡金属取代的钨硅杂多配合物αＳｉＷ１１Ｍｘ－（Ｍ＝ＭｎⅢ、ＦｅⅢ、ＣｏⅢ）的Ｋ（或Ｃｓ）盐，通过元素分析、红外、紫外、可见光谱、循环伏安等手段进行了表征．研究了配合物的热稳定性、水溶液中的酸碱稳定性、催化活性以及磁性，常温和变温（８２Ｋ～２７２Ｋ）磁化率数据表明配合物具有顺磁性特征．

金属催化合成呋喃衍生物的最新进展

综述了近几年来利用金属催化合成多取代呋喃环的方法。分两大类介绍:一是通过对呋喃环进行结构改造,即呋喃金属试剂在过渡金属催化下与卤化物或酰氯发生偶联反应得到,或呋喃卤化物与金属试剂、烯烃、炔烃偶联得到;二是以非环状化合物为前体进行呋喃环的构筑,即在金属试剂催化下,1,2-联烯基酮、β-碘代-β-烯酮、叁键在α,β-、β,γ-、γ,δ-的炔酮、4-炔-2-烯醇可以关环得到多取代的呋喃产物。此外,在Ru_2(OAc)_4催化下,α-叠氮酮与炔烃反应得到金属卡宾中间体,然后关环也可得到取代呋喃产物。

2-氰基-4’-甲基联苯合成方法综述

2-氰基-4′-甲基联苯(沙坦联苯)是合成血管紧张素Ⅱ拮抗剂类药物的天键中间体。综述了沙坦联苯的合成方法,并着重讨论了过渡金属催化偶联法在沙坦联苯合成中的应用。

碳糖苷合成的新进展

本文介绍了近几年来有关碳糖苷合成的最新进展,包括亲电取代、亲核糖取代、过渡金属催化、异头碳自由基反应、重排和环加成反应以及糖环形成反应等。

磷钨磷钼钨Dawson型杂多化合物的合成

Three new Dawson-type HPCs:K14·24H2O,K15H3·26H2O and K15H3·27H2O were synthesized for the first time.They are tungstophosphoric and molybdotungstophosphoric HPCs substituted by Ni or Cu.The intermediate product K10Na2H2P2W16O60 was synthesized from Na2WO4·2H2O and Na4HPO4·12H2O.The structures of the compounds were confirmed by IR,UV,XAFS and elemental analysis.

催化在有机合成中的新进展

近年来,过渡金属催化的卤代芳烃与各种亲核试剂的偶联反应已成为构筑C―C或C―杂原子键的有效手段,例如著名的Suzuki、Kumada、Stille、Negishi等生成C―C键的偶联反应等。最近,C―H键的直接活化及功能化方面有了一些突破。介绍了这一领域的新进展。

用于直接甲醇燃料电极的阳极催化剂研究

为了提高直接甲醇燃料电池阳极催化活性,本文研究了三种过渡金属取代磷钼酸修饰铂电极在硫酸溶液中的电化学行为及对甲醇的电催化氧化作用,并利用一氧化碳吸附实验评价了三种过渡金属取代磷钼酸修饰铂电极的抗一氧化碳毒化性能。结果表明,三种过渡金属取代磷钼酸修饰铂电极均能够提高铂电极的催化活性,其中PMnMo11修饰铂电极对甲醇的催化活性最高,同时铂电极经三种过渡金属取代磷钼酸修饰后抗一氧化碳毒化能力增强。

过渡金属甲基磺酸盐催化醇的四氢吡喃化反应

以过渡金属甲基磺酸盐[Mn(CH3SO3)2·2H2O,Cu(CH3SO3)2·4H2O,Co(CH3SO3)2·4H2O和Zn(CH3SO3)2·4H2O]为催化剂,在室温条件下催化醇的四氢吡喃化反应,并对反应条件进行了优化。结果表明:当醇用量为30 mmol,醇和3,4-二氢吡喃摩尔比为1.0∶1.1,甲基磺酸盐用量为1 mmol,二氯甲烷20 m L时,可高效催化醇的四氢吡喃化反应。与路易斯酸催化活性相比,过渡金属甲基磺酸盐催化醇的四氢吡喃化反应效果最好,催化酚的效果较差。用Mn(CH3SO3)2·2H2O和Cu(CH3SO3)2·4H2O催化正丁醇的四氢吡喃化反应,重复使用5次,收率分别为89%和92%。