2-氨基查尔酮与烯基巴比妥酸的aza-Michael/Michael串联 反应合成新型四氢喹啉螺巴比妥酸类化合物

以1,4-二氮杂二环[2.2.2]辛烷(DABCO)为催化剂，2-氨基查尔酮与烯基巴比妥酸为原料，经aza-Michael/Michael串联反应合成了11个新型的四氢喹啉螺巴比妥酸类化合物，分离收率62%~94%, dr值均大于20/1，其结构经¹H NMR， ¹³C NMR和HR-MS(ESI)表征。     

螺环季酮酸衍生物的合成及生物活性研究

为了寻求新颖的螺环季酮酸先导化合物,以3 -(2,4-二氯苯基)-4-羟基-1-氧杂螺[4.5]癸-3-烯-2-酮为原料,合成了21个螺环季酮酸衍生物,其结构经1H NMR,ESI MS和元素分析确认,并测定了化合物6b的晶体结构.初步生物活性测定表明,此类化合物对朱砂叶螨、蚜虫和粘虫都具有很好的生物活性,尤其是化合物5g和5m对朱砂叶螨的LD50分别为35.12和22.39 mg/L,高于螺螨酯的LD50:45.20 mg/L;化合物5b对蚕豆蚜的LD50为21.90 mg/L,而螺螨酯对蚕豆蚜的LD50为174.13 mg/L.     

一种四氧螺环过氧化物的合成

本文报道了一种新型的含双过氧键的螺环化合物的合成。该合成以双氧水为过氧键来源，经酮羰基的缩酮交换反应在底物中引入两个过氧氢基。然后通过汞离子诱发的对双键的加成反应分别将两个过氧氢基的羟基端固定在碳骨架上，形成双过氧螺环结构。螺环两端都含酯基，可供进一步结构修饰、合成衍生物用。     

氰基亚胺与亚甲基二氢苯并呋喃二酮类化合物的[3+2]环加成反应:螺吡唑类化合物的合成

采用具有环外双键的二氢苯并呋喃二酮类化合物和氰基亚胺的[3+2]环加成反应,在温和条件下,以高产率(78%~94%)和高非对映选择性(>20∶1dr)构建了一系列具有螺环结构的吡唑类化合物.     

硫代丁内酯拼接吡唑啉酮双螺环化合物的合成

以3-异硫氰酸酯取代的硫代丁内酯1为合成子,在有机催化剂DABCO作用下,与各种取代的吡唑啉酮烯烃2发生Michael加成与环化反应,获得了9个未见文献报道的新型硫代丁内酯拼接吡唑啉酮双螺环化合物3a～3i,产率70%～77%,dr 2/1～9/1,其结构经¹H NMR,¹³C NMR和HR-MS(ESI-TOF)表征,通过单晶进一步确定了化合物3c的构型。该类化合物含有螺环丁内酯和螺环吡唑啉酮生物活性骨架,对医药行业具有重要的潜在价值。     

含手性侧链结构的1, 5-二氮环辛烷的合成

手性α-氨基醇和原氯乙酸三乙酯作用,可同时分离得到两种手性侧链：酰胺醇(2a,2b)和恶唑啉(2c,2d);分别和1,5-二氮环辛烷反应,生成带手性侧臂的1,5-二氮环辛烷化合物(1a～1d),其结构经红外、核磁、质谱和元素分析等得到了证实。     

一种吲哚螺吡咯多取代杂环化合物的合成及其晶体结构

利用多组分1,3偶极环加成反应方法,合成了一种新的螺环结构1'-甲基-3'-吡啶甲酰基-4'-(2-噻吩基)螺[吲哚啉-3,2'-吡咯啉]-2-酮化合物,并对该化合物进行了红外光谱、核磁共振谱及X-射线单晶衍射表征.单晶衍射结果表明:该晶体属于三斜晶系,空间群为P-1,晶体参数为a=0.899 9(1)nm,b=0.914 4(1)nm,c=1.271 1(2)nm,α=92.852(1)°,β=107.305(2)°,γ=101.580(1)°.在分子晶体结构中,吡咯啉环采用了信封式构象,通过螺碳原子与吲哚啉环相连,形成刚性螺环结构,2个环接近垂直构型,其二面角为84.15(2)°.     

光/电化学驱动螺环化合物的合成研究进展

螺环作为一种重要的有机分子骨架,在有机化学、药物化学、材料科学等领域中广泛存在.由于螺环骨架具有较大的三维空间结构,满足药物设计中对构象刚性的需求,因此开发高效的螺环化合物的合成方法尤为重要.近年来,光催化和电催化作为绿色、高效的合成手段,为螺环化合物的合成注入了新的潜力.主要按螺[4.5]类骨架、螺[5.5]类骨架、螺[2.3]类骨架以及螺吲哚类骨架的构建进行了分类,并从光催化和电催化合成两个方面对螺环化合物的构建进行了综述.     

手性环丙烯构建策略用于对映选择性合成偕二氟亚甲基三元环化合物

作为最小的不饱和环状分子,环丙烯独特的刚性结构和多变的反应活性吸引了化学家的研究兴趣.自1922年Demjanov[1]报道了环丙烯化合物的首例合成以来,现已发展了一系列环丙烯的合成方法.手性环丙烯的合成是通过炔烃和重氮化合物的[2+1]不对称环加成反应.根据底物的不同,这些不对称环加成反应可以分为四类:(a)末端炔烃和单取代重氮化合物的反应,(b)末端炔烃和双取代重氮化合物的反应,(c)非末端炔烃和双取代重氮化合物的反应,(d)非末端炔烃和单取代重氮化合物的反应.在这四类反应中,末端炔烃和单取代重氮化合物的不对称反应相对容易进行.1992年,Doyle和Müller等[2]报道了手性铑催化剂[Rh2(5R-MEPY)4]促进的末端炔烃和重氮醋酸酯之间的不对称环丙烯基化反应(Scheme 1a).随后各种手性催化剂包括[Rh2(OAc)-(DPTI)3][3]、Ir(salen)衍生物[4]和[Co(3,5-diMes-Chen-Phyrin)][5]等被先后报道用于末端炔烃和单取代重氮化合物的不对称[2+1]环加成反应.     

新型多环吡咯并双螺环色满酮氧化吲哚类化合物的合成

以3-羟甲基色酮为原料,在4-二甲氨基吡啶催化下与(Boc)2O反应生成中间体A;A与靛红和脯氨酸生成的1,3-偶极子发生[3+2]环加成反应,合成了8个未见文献报道的多环吡咯并双螺环色满酮氧化吲哚类化合物(3a^3h),收率50%~67%,dr值4/1~2/1,其结构经^1H NMR,^13C NMR和HR-MS(ESI-TOF)表征。确定了化合物3a(CCDC:1973858)和3g(CCDC:1973859)的相对构型。结果表明:该类化合物含有连续5个立体中心,包括两个螺环季碳中心。     

二氧化碳和丙烯直接合成甲基丙烯酸的NiPMo/TiO2催化剂的研究

用溶胶-凝胶法以磷钼酸(MPA)的镍盐溶液水解钛酸四丁酯制备了NiPMo/TiO2催化剂.使用ICP、 XRD、 TG-DTA、 IR、 TPD-MS和微反应技术研究了催化剂的化学组成、热稳定性、化学吸附性质和催化反应性能.杂多钼酸盐与TiO2通过O2-在TiO2表面发生了键合.在623 K下,杂多阴离子仍保持原有的Keggin结构.CO2在Lewis酸位Ni(Ⅱ)和Lewis碱位Ni-O-Mo的桥氧协同作用下生成CO2卧式吸附态Ni(Ⅱ)←O-(CO)←(O--Ni).丙烯有多种吸附态在催化剂上吸附.在563 K、 1 MPa和空速1500 h-1的反应条件下,丙烯的摩尔转化率为3.2%,产物MAA选择性为95%.     

Synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives

Different approaches for the synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives from simple amino acids have been investigated. A library of 33 precursors for the preparation of N-hydroxy pyrazinones was obtained in moderate to good yields.     

Toward new camptothecins. Part 6: Synthesis of crucial ketones and their use in Friedländer reaction

In the context of the preparation of camptothecin and luotonin A analogs, the synthesis of some key keto-precursors and their use in Friedländer condensation are described. This paper also focuses on the stability of these keto intermediates and emphasizes the major differences between indolizinones and pyrroloquinazolinones series. Noteworthy is also the report of some original structures isolated as by-products of some experiments.     

CoFe2O4自形成磁性液体场致结构化对磁化的影响

The Langevin paramagnetic theory can’t describe the relation between magnetization of ferrofluids and applied magnetic field. The structuralization of ferrofluids, which is considered the main influence factor of the magnetization, is regarded. The part of magnetization works is deposited when the structure is forming. This action influences the magnetization of ferrofluids directly or indirectly. On the base of the “compressing” model, the Langevin function that usually describes the magnetization of ferrofluid is modified, and a well-fitted curve is obtained. An equation of the relation between the equivalent volume fraction after being “compressed” and the intensity of magnetic field is discovered, which approximately describes the process of magnetization. The relation between the approximate initial susceptibility and the volume fraction can be obtained from modified formula.     

Highly regioselective Buchwald–Hartwig amination at C-2 of 2,4-dichloropyridine enabling a novel approach to 2,4-bisanilinopyridine (BAPyd) libraries

The highly regioselective Buchwald–Hartwig amination at C-2 of the cheap and readily accessible reagent, 2,4-dichloropyridine with a range of anilines and heterocyclic amines is described. This new methodology is robust and provides a facile access to 4-chloro-N-phenylpyridin-2-amines on 0.25 mol scale. These intermediates undergo a further Buchwald–Hartwig amination at higher temperature to enable rapid exploration of the chemical space at C-4 and to provide a library of 2,4-bisaminopyridines.     

KMnO4-mediated oxidative CN bond cleavage of tertiary amines: Synthesis of amides and sulfonamides

KMnO₄-mediated oxidative CN bond cleavage of tertiary amines producing secondary amine was introduced, which was trapped by electrophiles (acyl chloride and sulfonyl chloride) to form amides and sulfonamides. The reaction could take place at mild condition, tolerating a wide range of function groups and affording products in moderate to excellent yields.     

Chemistry of heterocyclic compounds at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences, over 50 years (Review)

The review contains a concise historical account and information on the most significant researches undertaken by the staff at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences on the Chemistry of Heterocyclic Compounds. Dedicated to Academician of the Russian Academy of Sciences B. A. Trofimov on his 70th jubilee. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1443–1502, October, 2008.     

Sulfur-directed metal-free and regiospecific methyl C(sp3)–H imidation of thioanisoles

Regiospecific and direct imidation of the methyl C(sp³)–H bond of thioanisoles is realized under mild and metal-free conditions with N-fluorobis(benzenesulfonyl)imide as an oxidant and nitrogen source. Proposed mechanism suggests that thionium ion intermediates and a Pummerer-type reaction are involved. The imidation has advantages such as high step-economy, excellent functionality tolerance, and regiospecificity, giving structurally diverse imidation products.     

A general and convenient synthesis of 4-(tosylmethyl)semicarbazones and their use in amidoalkylation of hydrogen,heteroatom, and carbon nucleophiles

A general synthesis of previously unknown semicarbazone-based α-amidoalkylating reagents, 4-(tosylmethyl)semicarbazones, has been developed. The synthesis involved three-component condensation of semicarbazones of aliphatic or aromatic aldehydes with the same or other aldehydes and p-toluenesulfinic acid. The scope and limitations of this reaction were investigated. The compounds obtained were demonstrated to be an efficient α-(4-semicarbazono)alkylating agents. They were reacted with H- (sodium borohydride), O- (sodium methylate), S- (sodium phenylthiolate), N- (pyrrolidine, sodium succinimide), P- (trialkyl phosphites), and C-nucleophiles (sodium diethyl malonate) to give the corresponding products of the tosyl group substitution, 4-substituted semicarbazones, including analogues of nitrofurazone. Among the prepared compounds tested in vitro for antibacterial and antifungal activity, three nitrofuryl-containing semicarbazones exhibited high biological activities with minimum inhibitory concentration (MIC) values of 8–32 μg/mL.     

Synthesis of novel chiral bidentate hydroxyalkyl-N-heterocyclic carbene ligands and their application in palladium-catalyzed Mizoroki–Heck couplings and asymmetric addition of diethylzinc to benzaldehyde

A small library of new chiral bidentate hydroxyalkyl-imidazolium salts 1 is conveniently synthesized on multi-gram scale from inexpensive and commercially available chiral pool amino acids. The corresponding carbenes, generated by deprotonation of imidazolium salts 1, in combination with palladium(II) chloride were tested in the Mizoroki–Heck coupling reaction. The most significant results in terms of yields and reactivities were achieved with low catalyst loading. The catalytic activities of these imidazolium salts were also investigated in the asymmetric addition of diethylzinc to benzaldehyde. The use of MgO nanoparticles as an additive in conjunction with these ligands played a crucial role in increasing the efficiency of these reactions.