绿色路易斯酸三卤化铟在有机合成中的应用

三卤化铟作为温和的路易斯酸可在水、醇等绿色溶剂中实现高化学选择性、高 区域选择性和高立体选择性的化学转化。综述了三卤化铟在羟醛反应和类羟醛-曼 尼希反应、Fiedel-Crafts反应、环氧化合物的重排反应、α-氨基膦酸的合成、喹 啉环系的构建、酯交换反应、Diels-Alder反应和杂Diels-Alder反应,手性呋喃二 醇的合成、水相中的叠氮解反应和二硫缩醛的制备中的应用,同时还总结了本课题 组将三卤化铟应用于Biginelli反应和还原脱氧反应的反应结果。三卤化铟在有机 合成中潜在的优势将推动“绿色化学”的发展。     

Reaction path synthesis methodology for waste minimization

Being the core of whole process, a chemical process is a key step for reducing waste generation. Therefore, to organize a reasonable reaction path is very important for reducing waste emission. Because of the large amount of the feasible reaction path and other factors in a chemical reaction system, the opti-mizing for reaction path is difficult. Since the reaction path synthesis problem has presented, lots of re-searchers focused on it. At the beginning, only chem-ists took the research work,…     

Synthetic studies on (+)-naphthyridinomycin: stereoselective synthesis of the tetracyclic core framework

[reaction: see text] The stereoselective synthesis of the tetracyclic intermediate 21 for (+)-naphthyridinomycin (1) has been accomplished. The convergent synthesis used the Ugi 4CC reaction with the amine derivative 10. The key features of the stereoselective synthesis of 21 were the intramolecular Mizoroki-Heck reaction, an aromatic-aldehyde cyclization, and a stereoselective hydroboration.     

STUDY OF Cu-Mu CATALYST FOR THE SYNTHESIS OF METHYL FORMATE AND METHANOL FROM SYNTHESIS GAS

将一种新型的ＣｕＭｎ催化剂用于由合成气合成甲酸甲酯和甲醇，该催化剂表现出良好的反应活性和甲酸甲酯选择性。考察了反应温度、合成气压力及催化剂制备方法等对合成甲酸甲酯和甲醇的反应活性及选择性的影响。在反应条件下，产物收率最高达６０．１０ｇ／（Ｌ·ｈ），产物甲酸甲酯的选择性很高。用ＢＥＴ、ＸＲＤ及ＸＰＳＡｕｇｅｒ等测试方法对催化剂的比表面、晶相组成以及铜、锰在催化剂中的价态进行了表征，并探讨了催化剂失活的原因。     

A New Method of Low Temperature Methanol Synthesis

Low temperature methanol synthesis is a promising technique for the practical methanol industry. New developments of a new kind of low temperature methanol synthesis were reviewed, including the effects of feed gas, reaction solvent, supercritical media and catalyst modification. The reaction mechanism and kinetics were also summarized primarily. Carbon dioxide played an important role in this new kind of low temperature methanol synthesis. It reacted with hydrogen adsorbed on catalyst surface to form HCOOM, an important reaction intermediate. Alcohol solvent in the low temperature methanol synthesis performed not only a media, but also a homogeneous catalyst. The reaction of the adsorbed formate species with alcohol on Cu/ZnO catalyst surface proceeded according to the Rideal mechanism rather than Langmuir–Hinshelwood mechanism to form alkyl formate. The formation of alkyl formate from alcohol solvent and hydrogenation of such an alkyl formate were the key steps in low temperature methanol synthesis reaction. These results provided new insights into low temperature methanol synthesis.     

Stereocontrolled total synthesis of (-)-ephedradine A (orantine)

The stereocontrolled total synthesis of (-)-ephedradine A has been accomplished. The synthesis features an asymmetric C-H insertion reaction, an intramolecular ester-amide exchange reaction, and a Sharpless asymmetric aminohydroxylation reaction. Construction of the complex macrocyclic ring was performed by Ns-strategy and an intramolecular aza-Wittig reaction.     

分子内Friedel-Crafts环化反应在苯并环状物合成中的应用

Friedel-Crafts反应是有机合成中最有用的反应之一,它的应用范围十分广泛.Friedel-Crafts反应也是合成环状化合物的重要途径,尤其分子内的环化反应一直以来受到广泛的关注.对近年来应用分子内Friedel-Crafts环化反应合成苯并环状化合物进行了详细的综述,并对分子内Friedel-Crafts环化反应在有机合成上发展前景作了展望.     

Intermediacy of silylene and germylene in direct synthesis of organosilanes and organogermanes

In the direct synthesis of silicon compounds by reactions of elemental silicon with methyl chloride, methanol and hydrogen chloride, silylene formed on surface of silicon grains during the reaction is an intermediate. The reaction of surface silylene with a variety of unsaturated hydrocarbons provides new direct synthesis of organosilanes. In the direct synthesis of methylchlorogermanes from elemental germanium, surface germylene is not an intermediate, while tetrachlorogermane is synthesized by the direct reaction of germanium with hydrogen chloride via dichlorogermylene intermediate. Various unsaturated hydrocarbons or organic chlorides added to the system of tetrachlorogermane synthesis give new methods for the synthesis of organogermanes.     

Stereoselective total synthesis of (+)-polyrhacitide A

A facile stereoselective total synthesis of secondary metabolite (+)-polyrhacitide A is described. Stereoselective aldol reaction, Horner-Wardsworth-Emmons reaction, Evans acetal intramolecular oxa-Michael reaction and diastereoselective syn reduction reaction are the key steps involved in the target synthesis.     

A simple and efficient approach for the synthesis of 2-aminated quinazoline derivatives via metal free oxidative annulation

A simple and efficient approach for the synthesis of 2-aminoquinazoline derivatives in moderate to good yields. This reaction employs mild reaction conditions, is metal-free and utilizes readily available starting materials making it a more viable reaction for scale up synthesis and ligand diversity. Notably, this methodology allows for the synthesis of 2-aminoquinazolines using a free amine or cyclic amine enabling structural diversity and good atom economy.     

14C-labeled and large-scale synthesis of the angiotensin-(1-7)-receptor agonist AVE 0991 by cross-coupling reactions

The synthesis of (14)C-labeled AVE 0991 ((14)()C-1a) and large-scale synthesis of AVE 0991 (1a) are described. In the key step of the synthesis, the C-C coupling reaction of the imidazole (2) and thiophene (3) building blocks was studied under Suzuki and Stille reaction conditions, respectively. Suzuki reaction gave only moderate yields, whereas the best results were obtained under Stille reaction conditions with up to 64% yield.     

Intermediacy of silylene and germylene in direct synthesis of organosilanes and organogermanes

In the direct synthesis of silicon compounds by reactions of elemental silicon with methyl chloride, methanol and hydrogen chloride, silylene formed on surface of silicon grains during the reaction is an intermediate. The reaction of surface silylene with a variety of unsaturated hydrocarbons provides new direct synthesis of organosilanes. In the direct synthesis of methylchlorogermanes from elemental germanium, surface germylene is not an intermediate, while tetrachlorogermane is synthesized by the direct reaction of germanium with hydrogen chloride via dichlorogermylene intermediate. Various unsaturated hydrocarbons or organic chlorides added to the system of tetrachlorogermane synthesis give new methods for the synthesis of organogermanes.     

Facile Total Synthesis of Benzo[b]furan Natural Product XH-14

An efficient and practical total synthesis of benzo[b]furan natural product XH-14 is demonstrated in nine steps from vanillin. Introduction of iodide substituents in the reaction including optimization of the reaction sequences is essential for the successful synthesis of XH-14. Sonogashira coupling with iodobenzene, iodine-induced cyclization, Wittig reaction, and formylation are critical in the high-yield total synthesis of XH-14.     

A stereoselective synthesis of (+)-herboxidiene/GEX1A

A stereoselective synthesis of (+)-herboxidiene is described. The convergent synthesis utilized a Suzuki cross-coupling reaction to assemble the key segments. The synthesis of the functionalized tetrahydropyran ring utilized an Achmatowicz reaction as the key step. The synthesis of the C10-C19 segment was accomplished using Brown's crotylboration, asymmetric alkylation, and a stereoselective allylic chlorination reactions.     

Synthesis of arylstannanes by palladium-catalyzed desulfitative coupling reaction of sodium arylsulfinates with distannanes

A novel Pd-catalyzed desulfitative cross-coupling reaction of sodium arylsulfinates with hexaalkyl distannanes is realized, allowing the facile synthesis of functionalized arylstannanes with moderate to excellent yields. The successful implement of gram-scale synthesis and tandem Stille coupling reaction demonstrates the potential applications of this method in organic synthesis.     

Chichibabin pyridinium synthesis

Chichibabin pyridine synthesis involves the reaction of three aldehydes and ammonia to form 2,3,5-trisubstituted pyridines. This study examined the synthesis of tetrasubstituted pyridinium from aldehydes and an amine hydrochloride in the presence/absence of Pr(OTf)₃. Important insights into the reaction mechanisms of Chichibabin pyridinium synthesis were proposed through the investigation of reaction intermediates along with quantitative GC–MS analysis.     

Divergent approach to flavones and aurones via dihaloacrylic acids. Unexpected dependence on the halogen atom

The reaction of phenols with 7a led to the synthesis of aurones, while the reaction of phenols with 7b led to the synthesis of flavones.     

有机硼酸类催化剂在有机合成中的应用

综述了有机硼酸类作为催化剂应用于有机合成反应中的最新研究进展, 重点介绍了所发现的各种有机硼酸催化剂在缩合反应、羧酸还原反应、Diels-Alder反应中的催化活性以及反应机理. 硼酸催化剂因具有催化效率高、反应条件温和、可重复使用等优点, 必将在有机合成催化领域中得到更广泛的应用.     

低共熔溶剂催化有机合成反应的研究进展

低共熔溶剂(DESs)是一种新型的离子液体(ILs)类似物,与传统有机溶剂、离子液体相比,DESs具有低毒、廉价、易于合成、生物可降解性等特点,因此在众多领域广受关注。近年来DESs在有机合成领域备受关注,被广泛用作合成反应的溶剂、催化剂、反应物等,在有机反应方面存在很大发展空间,本文综述了DESs在有机合成反应中的应用,重点讨论其在氧化还原反应、取代反应、缩合反应、环化反应等方面的研究进展,为其开发应用提供新思路。     

Total synthesis of (+)-acutiphycin

Synthetic studies toward the total synthesis of (+)-acutiphycin (1) resulted in the discovery of additive-free, highly regioselective nickel-catalyzed reductive coupling reactions of aldehydes and 1,6-enynes and the construction of an advanced intermediate in studies directed toward the synthesis of 1. Ultimately, although not employing the nickel-catalyzed reaction, a highly convergent total synthesis of (+)-acutiphycin featuring an intermolecular SmI2-mediated Reformatsky coupling reaction and macrolactonization initiated by a retro-ene reaction of an alkoxyalkyne was achieved. The resulting synthesis was 18 steps in the longest linear sequence from either methyl acetoacetate or isobutyraldehyde.