The alkaloids of Abuta imene and Abuta rufescens

The alkaloid fraction of either Abuta imene or Abuta rufescens was found to contain the oxoaporphines imenine, homomoschatoline, and imerubrine, as well as the azafluoranthenes imeluteine, rufescine and norrufescine. Structures are proposed for the new alkaloids imerubrine and norrufescine, and a synthesis of homomoschatoline is described.     

Isophellibilidine,a new alkaloid of Phelline billiardieri: structure and hemisynthesis

Structure $\text{3}$ proposed for isophellibilidine is confirmed by partial synthesis from the major alkaloid of $\text{Phelline billiardieri}$.     

Ferric nitrate-promoted oxidative esterification of toluene with N-hydroxyphthalimide: Synthesis of N-hydroxyimide esters

A ferric nitrate-promoted cross-dehydrogenative coupling reaction of N-hydroxyphthalimide (NHPI) with toluene derivatives is reported. The reaction proceeded smoothly using molecular oxygen as an oxidant, providing an efficient method for the synthesis of N-hydroxyimide esters. Furthermore, a plausible mechanism was proposed.     

An efficient unprecedented synthesis of novel functionalized imidazoles from secondary amino-N-carbothioic acid (phenyl-p-tolylimino-methyl)amides and dimethyl acetylenedicarboxylate

The synthesis of functionalized imidazoles in a single-pot from the reactions of secondary amino-N-carbothioic acid (phenyl-p-tolylimino-methyl)amides with dimethyl acetylenedicarboxylate is reported. A plausible mechanistic pathway for the formation of the imidazoles is proposed.     

l-Proline catalyzed domino Michael addition of N-substituted anilines

Here we report l-proline catalyzed 3-component reaction of indoles, aldehydes and N-substituted anilines in water as solvent at room temperature for the synthesis of 3-(α,α-diarylmethyl)indoles. The reaction is in fact a Michael addition of N-substituted anilines to alkylideneindolenines. The reaction is very clean, high yielding and having broad substrate scope. A tentative mechanism is proposed.     

A facile high-yield solvothermal route to tin phosphide Sn4P3

An effective method of synthesis of tin phosphide Sn₄P₃ starting from metallic tin and amorphous red phosphorus by a low-temperature (200 °C) solvothermal reaction in ethylenediamine is offered. The key parameters of this process - duration, temperature, and the ratio of initial components (Sn/P) are studied. The structure, phase composition, and morphology of the products are investigated using powder X-ray diffraction and scanning electron microscopy. Different synthetic ways for tin phosphide are discussed and compared with the proposed one. The mechanism of solvothermal preparation of tin phosphide in ethylenediamine is discussed. It is shown that the proposed solvothermal method opens up the possibility of preparing other metal-rich phosphides.     

Synthesis of (2s,3r,4e,8e)-n-(2′r)-2′-hydroxyhexadecanoyl-9-methyl-4,8-sphingadienine,the ceramide portion of the fruiting-inducing cerebroside in a basidiomycete schizophyllumcommune

A total synthesis of the natural enantiomer of the title compound was accomplished, which confirmed the structure proposed for the fruiting-inducing cerebroside of $\text{Schizophyllum}$$\text{commune}$.     

An efficient synthesis of 7-hydroxy-2,6-dimethylchromeno[3,4-d]oxazol-4-one—a protected fragment of novenamine

The high-yielding six-step synthesis of 7-hydroxy-2,6-dimethylchromeno[3,4-d]oxazol-4-one 17 from commercially available 2,4-dihydroxy-3-methylacetophenone is described. Coumarin 17 constitutes a useful synthon for coumarin antibiotic synthesis. A new methodology for oxazole formation applicable to 3-aminocoumarins has been developed, and a mechanistic rationalization is proposed.     

Microwave-promoted efficient conversion of acetophenones to 1,3,5-triarylbenzenes catalyzed by H3PW12O40 and nano-silica supported H3PW12O40 as reusable catalysts

H₃PW₁₂O₄₀ and nano-silica supported H₃PW₁₂O₄₀ were found to be efficient heterogeneous catalysts for the preparation of 1,3,5-triarylbenzenes via triple self condensation of acetophenones under microwave irradiation and solvent-free conditions. High yields, short reaction times, easy work-up, easy availability and handling, eco-friendly and reusability of the catalysts are the main aspects of the present method. The catalytic mechanism of 1,3,5-triarylbenzenes synthesis is also proposed.     

添加碳元素合成化学计量比LiNiO2

本文采用添加碳元素、葡萄糖及使用多种试剂为原料的合成方法,合成了具有化学计量比的LiNiO2.分析了这些方法在合成反应中的作用,同时给出了合成LiNiO2的最佳反应条件.     

Stereoselective aldol-type cyclization reaction mediated by dibutylboron triflate/diisopropylethylamine

[reaction: see text] Dibutylboron triflate/diisopropylethylamine mediated aldol-type cyclization provides an expedient route for the stereoselective synthesis of cyclic ethers in a single step. The method is highly efficient for the stereoselective synthesis of 4-cis-tetrahydropyranones. The reaction is proposed to proceed via an S(N)1-type mechanism through a chair-like transition state, in which both substituents occupy equatorial positions.     

The efficient one-pot synthesis of tetraalkyl substituted furans from symmetrical acetylenes,EtAlCl2, and carboxylic esters catalyzed by Cp2TiCl2

A new one-pot method for the synthesis of tetraalkyl substituted furans in 74–80% yields has been implemented via the reaction between symmetrical acetylenes, ethylaluminum dichloride, and carboxylic esters in the presence of metallic Mg as an acceptor of halide ions, catalyzed by bis(cyclopentadienyl)titanium dichloride. A mechanism for the reaction is proposed and discussed.     

Synthesis of l-aminohomohistidine (l-Ahh)

A short synthesis of l-aminohomohistidine (l-Ahh), which starts from readily available δ-hydroxy-l-lysine is described. The embedding of the basic guanidino moiety in the aromatic imidazole lowers the basicity of the side chain to a pK_a of 8.3. It is proposed that l-Ahh may be employed as an arginine-mimetic in medicinal chemistry.     

Methanol facilitated synthesis of 7-methoxy-2-thioxo-2,3-dihydro-1H-1,3-diazepin-4(7H)-ones from nitroallylic acetates and thiourea

A novel efficient strategy for the synthesis of rare 7-methoxy-2-thioxo-2,3-dihydro-1H-1,3-diazepin-4(7H)-ones is described. Methanol, solvent for this one-step reaction, participated in this seven-membered ring closure reaction between nitroallylic acetates and thiourea. The thiourea itself also served as a base in this reaction. A possible mechanism for the reaction is proposed.     

Synthesis of substituted N-hydroxyureas via the in situ generation of t-butoxy isocyanate

Treatment of primary and secondary amines with tert-butylmesitylenesulfonoxycarbamate and a base afforded tert-butoxyurea, which when treated with an acid ultimately yielded substituted N-hydroxyureas. It is proposed that this proceeded via the generation of t-butoxy isocyanate in situ. This method allows for the synthesis of both mono and disubstituted N-hydroxyureas.     

An unusual involvement of NaIO4 in the acetylation of bisphenol during attempted oxidative acetylation

An unexpected behaviour of compilation of reagent sodium metaperiodate in acetic anhydride for acetylation of bisphenols was observed during attempted oxidative acetylation of bisphenols for the synthesis of a bis-acetoxy cyclohexadienone. The products were characterized by their spectral and analytical data and a probable mechanism for acetylation involving role of NaIO₄ is proposed.     

Novel oxidative nitrogen to carbon rearrangement found in the conversion of anilines to benzaldoximes by treating with HCHO/H2O2

Novel rearrangement was found by reacting anilines with HCHO/H₂O₂ resulting in the synthesis of various benzaldoximes. The mechanism of the rearrangement is proposed and suggested that the rearrangement might proceed via unstable N-phenyloxazirane intermediate followed by the transfer of aryl moiety from nitrogen to carbon atom leading to the formation of benzaldoxime.     

A relay to (+)-pleuromutilin. I. Denovo synthesis of a levorotatory tricyclic lactone subunit

Construction of the optically active lactone (?)?13, required for a proposed total synthesis of (+)-pleuromutilin, has been successfully achieved.     

Total Synthesis of (+)‐ and (−)‐Decursivine and (±)‐Serotobenine through a Cascade Witkop Photocyclization/Elimination/Addition Sequence: Scope and Mechanistic Insights

In this article, the total syntheses of antimalarial compound decursivine and its biologically inactive sibling serotobenine are presented. The biomimetic synthesis of (±)‐serotobenine was investigated first, but failed. During the subsequent investigation of other synthetic routes, we discovered a new cascade Witkop photocyclization/elimination/addition sequence, which enabled the expedient synthesis of not only racemic decursivine and serotobenine, but also enantiopure (+)‐ and (?)‐decursivine and a variety of their analogues. The present syntheses represent the shortest pathway for the total synthesis of decursivine and serotobenine to date. Moreover, the newly developed cascade sequence for the total synthesis of decursivine does not need any protecting steps. The scope and the reaction mechanism of the cascade sequence were also studied. A rational mechanism for the cascade sequence is proposed, which is consistent with the previous studies and our current experimental results.     

Synthesis of cyclic carbonates and dimethyl carbonate using CO<Subscript>2</Subscript> as a building block catalyzed by MOF-5/KI and MOF-5/KI/K<Subscript>2</Subscript>CO<Subscript>3</Subscript>

The synthesis of cyclic carbonates or dimethyl carbonate (DMC) using CO₂ as a building block is a very interesting topic. In this work, we found that the metalorganic framework-5 (MOF-5)/KI was an active and a selective catalytic system for the synthesis of cyclic carbonates from CO₂ and epoxides, and MOF-5/KI/K₂CO₃ was efficient for the preparation of DMC from CO₂, propylene, and methanol by a sequential route. The impacts of temperature, pressure, and reaction time length on the reactions were investigated, and the mechanism of the reactions is proposed on the basis of the experimental results.