Palladium-catalyzed synthesis of 2-(aminomethyl)indoles from ethyl 3-(o-trifluoroacetamidophenyl)-1-propargyl carbonate

[reaction: see text] The palladium-catalyzed reaction of ethyl 3-(o-trifluoroacetamidophenyl)-1-propargyl carbonate with piperazines in the presence of Pd(PPh(3))(4) in THF at 80 degrees C affords 2-(piperazin-1-ylmethyl)indoles in excellent yields. Good to excellent yields are also obtained with other secondary amines.     

合成文拉法星的2-氮杂-1,3-丁二烯杂Diels-Alder反应与其 单分子环合竞争反应的研究

研究了不同的Lewis酸催化剂、温度、微波等条件下, 4-(4-甲氧苯基)-1-苯基-3-三甲基硅氧基-2-氮杂-1,3-丁二烯(2-ABDE)和亲二烯体环己酮发生杂Diels-Alder反应生成[4＋2]的六元环合产物噁嗪酮衍生物, 伴随的2-ABDE的 [2＋2]单分子环合, 生成单环β-内酰胺衍生物. 结果表明: 在低温条件下如(－78 ℃)[4＋2]反应占主导; 而在高温条件下(如135 ℃)仅进行[2＋2]反应. 微波加热方式可显著提高[2＋2]反应的速率和产率. 不同的Lewis酸催化剂对[2＋2]反应和[4＋2]反应的催化效率不同. Lewis酸的酸性强弱、软硬对2-ABDE的[2＋2]反应的催化能力起决定性作用.     

Mo(CO)6- and [Rh(CO)2Cl]2-catalyzed allenic cyclocarbonylation reactions of alkynones: efficient access to bicyclic dienediones

Allenyl alkynones are efficiently transformed into fused bicyclic dienediones via cyclocarbonylation reaction conditions. Mo(CO)6/DMSO reaction conditions result in the formation of a bicyclo[3.3.0]octenone ring system, and the [Rh(CO)2Cl]2-catalyzed reaction affords bicyclo[4.3.0]nonenone and bicyclo[5.3.0]decenone scaffolds.     

ReO(N2O2)X] complexes: "4 + 1"?

[ReO(ppme)X] (where ppme(2-) is 2,5-diazo-N,N'-dimethylhexyl-1,6-bis(phenylphosphinate), X = Br0.3Cl0.7) has been synthesized via a substitution reaction and structurally characterized. The coordination geometry is a distorted octahedron and one phosphinate coordinates cis and the other trans to the oxo O atom. This coordination mode is conserved in all [ReOppmeX] complexes synthesized in this study. [ReO(ppme)Cl] has been prepared by a reduction/complexation reaction from [NH4][ReO4]. [ReO(ppme)Cl] reacts with thiocyanate and benzene thiolate forming [ReO(ppme)X] (X = (-)NCS, (-)SC6H5), but the one-pot synthesis of the respective ternary thiolate complexes from perrhenate was not successful. The reduction/complexation reaction of a thiol, H2ppmeCl4, and perrhenate resulted in the formation of [H3ppme][ReO(SR)4], the reaction of which with [ReO(ppme)Cl] does not lead to [ReO(ppme)SR] in high yields.     

含金属基团的四价锡化合物的合成和取代反应动力学

通式为[Fe(CO)~2Cp]~2Sn(Ar)Cl的化合物为一组新的化合物,由[Fe(CO)~2Cp]~2SnCl2与AgMgX反应合成.[Fe(CO)~2Cp]~2Sn(Ar)Cl与各种亲核试剂Y发生取代反应给出另一组新的化合物[Fe(CO)~2Cp]~2Sn(Ar)Y,其中[Fe(CO)~2Sn(p-MeC~6H~4)Br经X射线衍射分析确定结构.[Fe(CO)~2Cp]~2Sn(1,3,5-Me~3C~6H~3)Cl与NAS~2CNMe~2或KSCN在不同溶剂中的反应动力学表明,由于锡易形成高配位中间体,尽管锡上两个较大的金属基团带来一定空间障碍,反应仍主要按SN2机理进行.     

Synthesis and conformational study of the first triply bridged calix[6]azatubes

[reaction: see text] The first C(3)(v)- and D(3)(h)-symmetrical triply bridged calix[6]azatubes were prepared in good yields from the known 1,3,5-tris-methylated calix[6]arene through an efficient [1 + 1] macrocyclization reaction. A remarkably regioselective hexa ipso-nitration reaction led to a calix[6]azatube substituted at the wide rim in alternate position by tBu and nitro groups. A (1)H NMR study showed that, whereas the parent bis-calix[6]arenes self-include their methoxy groups, thereby closing their inner tube, the nitro-substituted calix[6]azatube undergoes a conformational change with the expulsion of the methoxy groups, hence presenting a three-dimensional structure open for host-guest applications.     

Investigations of the products of the reaction of epichlorohydrin with aromatic amines

Heating 3-hydroxy-1,2,3,4-tetrahydrobenzo[h]quinoline with phosphorus oxychloride gave a mixture of isomeric 3-chloro-1,2,3,4-tetrahydrobenzo[h]quinoline and 2-(chloromethyl)-benz[g]indoline, which are converted to a mixture of 3-benzoyloxy-1,2,3,4-tetrahydrobenzo-[h]quinoline and 2-(benzoyloxymethyl)benz[g]indoline on reaction with potassium benzoate. Saponification of 2-(benzoyloxymethyl)benz[g]indoline gave 2-(hydroxymethyl)benz[g]indoline. The reaction of the isomeric chloro derivatives with potassium cyanide gave 2-(benz[g]-indolinyl)acetonitrile.See [1] for communication IX.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 362–366, March, 1972.     

Mechanistic twist of the [8+2] cycloadditions of dienylisobenzofurans and dimethyl acetylenedicarboxylate: stepwise [8+2] versus [4+2]/[1,5]-vinyl shift mechanisms revealed through a theoretical and experimental study

Recently, it was reported that both dienylfurans and dienylisobenzofurans could react with dimethyl acetylenedicarboxylate (DMAD) to give [8+2] cycloadducts. Understanding these [8+2] reactions will aid the design of additional [8+2] reactions, which have the potential for the synthesis of 10-membered and larger carbocycles. The present Article is aimed to understand the detailed mechanisms of the originally reported [8+2] cycloaddition reaction between dienylisobenzofurans and alkynes at the molecular level through the joint forces of computation and experiment. Density functional theory calculations at the (U)B3LYP/6-31+G(d) level suggest that the concerted [8+2] pathway between dienylisobenzofurans and alkynes is not favored. A stepwise reaction pathway involving formation of a zwitterionic intermediate for the [8+2] reactions between dienylisobenzofurans that contain electron-donating methoxy groups present in their diene moieties and DMAD has been predicted computationally. This pathway is in competition with a Diels-Alder [4+2] reaction between the furan moieties of dienylisobenzofurans and DMAD. When there is no electron-donating group present in the diene moieties of dienylisobenzofurans, the [8+2] reaction occurs through an alternative mechanism involving a [4+2] reaction between the furan moiety of the tetraene and DMAD, followed by a [1,5]-vinyl shift. This computationally predicted novel mechanism was supported experimentally.     

Novel [6 + 2] cycloaddition of fulvenes with alkenes: a facile synthesis of the anislactone and hirsutane framework

[reaction: see text] In contrast to the Diels-Alder reaction of fulvenes and various alkenes, 6-aminofulvenes react with maleic anhydride (or maleimide) to give [6 + 2] cycloaddition adducts, constituting an efficient and novel route to pentaleno[1,2-c]furan, pentaleno[1,2-c]pyrrole, and cyclopenta[a]pentalene skeleton.     

Reaction of azole condensed quinoxaline N-oxides with acetic anhydride

The reaction of 7-chlorotetrazolo[1,5-α]quinoxaline 5-oxide 6a with acetic anhydride gave 7-chloro-5-(7-chlorotetrazolo[1,5-α]quinoxalin-4-yl)-4,5-dihydro-4-oxotetrazolo[1,5-α]quinoxaline 7a , while the reaction of 7-chloro-1,2,4-triazolo[4,3-α]quinoxaline 5-oxide 6b with acetic anhydride afforded 7-chloro-5-(7-chloro-1,2,4-triazolo[4,3-α]quinoxalin-4-yl)-4,5-dihydro-4-oxo-1,2,4-triazolo[4,3-α]quinoxaline 7b and 7-chloro-4,5-dihydro-4-oxo-1,2,4-triazolo[4,3-α]quinoxaline 8b . The reaction of compound 6a or 6b with acetic anhydride/acetic acid provided 7-chloro-4,5-dihydro-4-oxo-tetrazolo[1,5-α]quinoxaline 8a or compound 8b , respectively.     

Rhodium(I)-catalyzed intramolecular pauson-khand-type [2 + 2 + 1] cycloaddition of allenenes

[reaction: see text] The novel [RhCl(CO)(2)](2)-catalyzed [2 + 2 + 1] cycloaddition of allenenes leading to the bicyclo[4.3.0]non-1(9)-en-8-one as well as the bicyclo[5.3.0]dec-1(10)-en-9-one skeletons has been developed. This method also provides a new procedure for the construction of the bicyclo[4.3.0]non-1(9)-en-8-one skeleton having an alkyl appendage at the ring juncture, which was hardly attained in a satisfactory yield by the Pauson-Khand reaction of the corresponding enynes.     

Heterocyclizations with tosylmethyl isocyanide derivatives. A new approach to substituted azolopyrimidines

An efficient synthesis of substituted azolopyrimidines such as pyrido[3',2':4,5]pyrrolo[1,2-c]pyrimidines, pyrimido[1,6-a]indoles, benzo[4,5]imidazo-[1,2-c]pyrimidines, an imidazo[1,2-c]pyrimidine, and pyrazolo[1,5-c]pyrimidines is described. The method involves the reaction of N-protected bromomethylazoles and tosylmethyl isocyanide (TosMIC) derivatives in nonanhydrous media. The study of the reaction conditions shows that the method is only successful under phase-transfer conditions (CH2Cl2/30% aq NaOH) using benzyltriethylammonium chloride as a catalyst.     

Strain-Induced Ring Expansion Reactions of Calix[3]pyrrole-Related Macrocycles

The recent discovery of calix[3]pyrrole, a porphyrinogen-like tripyrrolic macrocycle, has provided an unprecedented strain-induced ring expansion reaction into calix[6]pyrrole. Here, we synthesized calix[n]furan[3-n]pyrrole (n=1∼3) macrocycles to investigate the reaction scope and mechanism of the ring expansion. Single crystal X-ray analysis and theoretical calculations revealed that macrocyclic ring strain increases as the number of inner NH sites increases. While calix[1]furan[2]pyrrole exhibited almost quantitative conversion into calix[2]furan[4]pyrrole within 5 minutes, less-strained calix[2]furan[1]pyrrole and calix[3]furan were inert. However, N-methylation of calix[2]furan[1]pyrrole induced a ring-expansion reaction that enabled the isolation of a linear reaction intermediate. The mechanism analysis revealed that the ring expansion consists of regioselective ring cleavage and subsequent cyclodimerization. This reaction was further utilized for synthesis of calix[6]-type macrocycles.     

Synthesis and deprotonation of P-H-functionalised phosph(III)azanes; borohydride dependency on the formation of cis- or trans-[HP(mu-NtBu)2PNtBuH

The reaction of [ClP(muNtBu)2PNtBuH] (1) with LiBsBu3H yields trans-[HP(muNtBu)2PNtBuH] (2), by contrast, reaction with LiBEt3H yields cis-[HP(mu-NtBu)2PNtBuH] (3). Compounds and represent the first examples of P-H-functionalised cyclophosph(III)azanes. Deprotonation of with BnNa (Bn=benzyl) gives the first example of a secondary phosphine-functionalised cyclodiphosph(III)azane anion [HP(mu-NtBu)2PNtBu]- (4).     

Reaction mechanism and chemoselectivity of intermolecular cycloaddition reactions between phenyl-substituted cyclopropenone ketal and methyl vinyl ketone

In this paper, the mechanisms of the intermolecular [3+2] and [1+2] cycloaddition reactions of 1,1/1,3-dipolar π-delocalized singlet vinylcarbenes, which is obtained from cyclopropenone, with an electron-deficient C═O or C═C dipolarophile, to generate five-membered ring products are first disclosed by the density functional theory (DFT). Four reaction pathways, including two concerted [3+2] cycloaddition reaction pathways and two stepwise reaction pathways (an initial [1+2] cycloaddition and then a rearrangement from the [1+2] cycloadducts to the final [3+2] cycloadducts), are investigated at the B3LYP/6-31G(d,p) level of theory. The calculated results reveal that, in contrast to the concerted C═O [3+2] cycloaddition reaction pathway, which is 7.1 kcal/mol more energetically preferred compared with its stepwise reaction pathway, the C═C dipolarophile favors undergoing [1+2] cycloaddition rather than concerted [3+2] cycloaddition (difference of 5.3 kcal/mol). The lowest free energy barrier of the C═O concerted [3+2] cycloaddition reaction pathway shows that it predominates all other reaction pathways. This observation is consistent with the finding that the C═O [3 + 2] cycloadduct is the main product under experimental conditions. In addition, natural bond orbital second-order perturbation charge analyses are carried out to explain the preferred chemoselectivity of C═O to the C═C dipolarophile and the origins of cis-stereoselectivity for C═C [1+2] cycloaddition. Solvent effects are further considered at the B3LYP/6-31G(d,p) level in the solvents CH(3)CN, DMF, THF, CH(2)Cl(2), toluene, and benzene using the PCM model. The results indicate that the relative reaction trends and the main products are insensitive to the polarity of the reaction solvent.     

Further study of the reaction of Fe2+ with CN-: synthesis and characterization of cis and trans [FeII,III(CN)4L2]n- complexes

The reaction of Fe2+ with CN-, which was first performed in 1704, has been used to synthesize a new series of basic [FeII,III(CN)4L2]n- complexes, where L is a monodentate ligand. trans-Na2[FeII(CN)4(DMSO)2] and cis-[NEt4]2[FeII(CN)4(pyridine)2] are synthesized by the direct reaction of FeCl2 with 4 equiv of CN- in DMSO or pyridine. Air oxidation of the latter compound gives cis-[NEt4][FeIII(CN)4(pyridine)2]. The non-cyanide ligands in these complexes undergo facile ligand exchange reactions with solvent. Reaction of cis-[NEt4]2[FeII(CN)4(pyridine)2] with CO at room temperature gives trans-[NEt4]2[FeII(CN)4(pyridine)(CO)].     

Heterocycles containing nitrogen and sulfur. Part 49. Synthesis of derivatives of new heterocyclic systems: 1,2-Dioxocyclopenta(hexa)[g]oxazolidino-[3,2-f] pyrimido[4,5-b][1,4]thiazine, 1,2-dioxocyclopenta(hexa)-[g] imidazolidino[3,2-f]pyrimido[4,5-b][1,4]thiazine, and 1,2-oxazino[5,4-g]pyrimidino[4,5-b][1,4]thiazine

The reaction of 4-methoxy-5-amino-6-mercaptopyrimidine with 2-oxo-1-chlorocyclopentyl(hexyl)glyoxalate esters gave derivatives of the previously unknown tetracyclic systems 1,2-dioxocyclopenta (hexa)[g]oxazolidino[3,2-f]pyrimido[4,5-b][1,4]thiazines, which are transformed by ammonium acetate into derivatives of 1,2-dioxocyclopenta(hexa) [g]imidazolidino[3,2-f]pyrimido[4,5-b]-[1,4] thiazines. Derivatives of the new tricyclic 1-oxazino [5,4-g]pyrimido[4,5-b][1,4]thiazine system were obrtained by reaction of 6-carbethoxy-7-acetylpyrimido [4,5-b] [1,4] thiazines with hydroxylamine.     

Thermal and palladium-catalyzed [3 + 2] synthesis of cyclopentadienone acetals from cyclopropenone acetals and acetylenes

[reaction: see text] Substituted cyclopentadienone acetals (CPDAs) were synthesized by a thermal or palladium-catalyzed [3 + 2] cycloaddition reaction of a substituted cyclopropenone acetal to an electron-deficient acetylene. The synthesis afforded di-, tri-, and tetra-substituted CPDAs of considerable structural varieties that undergo Diels-Alder reaction to produce bicyclo[2.2.1]heptenes.     

Reaction of bis(trimethylsiloxy)phosphine with trimethylsilane

Bis(trimethylsilyl) [3-(trimethylsilyl)propyl]phosphonate and trimethylsilyl [3-(trimethylsilyl)propyl]-phosphinate are obtained by the reaction of bis(trimethylsiloxy)phosphine with trimethylallylsilane and converted into [3-(trimethylsilyl)propyl]phosphinic and [3-(trimethylsilyl)propyl]phosphonic acid, respectively, by the reaction with methanol.     

瓜环基金属纳米催化剂的电化学研究进展（英文）

金属纳米材料在电催化应用中展示出良好的性能,但是它们依旧面临着稳定性差和调控策略有限的问题。引入第二组分是一种有效的策略,能够很好的改善其催化活性与稳定性。在这篇综述中,我们概述了结合金属纳米材料和瓜环（CB[n]）用于电催化应用。瓜环是一系列的具有刚性结构、高稳定性、与金属配位的官能团的大环,它们适合稳定金属纳米材料并对其进行调控。本文讨论按照瓜环的功能分类,包含瓜环作为保护剂、瓜环基的超分子自组装体以及瓜环作为前驱体制备氮掺杂多孔碳。多种金属纳米催化剂,包括金属纳米颗粒（Pt,Ir,Pd,Ru,Au）、金属单原子（Fe,Co,Ni）以及过渡金属碳化物（TMCs）成功与瓜环或瓜环衍生的碳材料复合,这些复合材料在许多电催化反应中展示出优异的性能和稳定性,反应包括了氧还原反应（ORR）、析氧反应（OER）、析氢反应（HER）、二氧化碳还原反应（CO2RR）、甲烷氧化反应（MOR）、乙醇氧化反应（EOR）。其中,一些金属-瓜环复合物可进一步作为双功能催化剂用于全水解和燃料电池中。瓜环基的纳米催化剂具有媲美商用催化剂的性能,甚至其稳定性可优于商用催化剂。实验分析以及密度泛函理论（DFT）计算...