Showing papers on "Polycyclic compound published in 2007"
TL;DR: Mechanistic investigation revealed that the kinetically favored ipso attack intermediates might undergo thermal skeletal rearrangement via 1,2-alkyl shift.
Abstract: Both 4-phenyl 1-lithio-1,3-butadienes and 4-naphthyl 1-lithio-1,3-butadienes underwent highly efficient and selective intramolecular nucleophilic addition of the butadienyllithium to the aromatic rings, resulting in full dearomatization of the phenyl rings and partial dearomatization of the naphthyl rings. When the reactions were carried out at lower temperatures, ipso intramolecular nucleophilic attack took place exclusively to afford the spirocyclopentadiene derivatives upon hydrolysis or further treatment with a variety of electrophiles. 4-Naphthyl 1-lithio-1,3-butadienes and 4-phenyl 1-lithio-1,3-butadienes were found to proceed in this reaction under similar conditions, with the former being faster even at -78 degrees C. However, when the reaction of 4-naphthyl 1-lithio-1,3-butadienes was carried out at higher temperatures, such as 75 degrees C, an interesting skeletal rearrangement took place to afford the vicinal attack products, tetrasubstituted phenanthrenes, via a dearomatization/rearomatization process. Mechanistic investigation revealed that the kinetically favored ipso attack intermediates might undergo thermal skeletal rearrangement via 1,2-alkyl shift.
29 citations
TL;DR: A new, efficient, and highly diastereoselective synthesis of polycyclic indole derivatives through intramolecular imino Diels-Alder reaction of aminoanthraquinone with N-prenylated indole-2-carboxaldehydes in the presence of 20 mol % of triphenylphosphonium perchlorate (TPPP) is reported with extremely high cis selectivity in good yield.
Abstract: A new, efficient, and highly diastereoselective synthesis of polycyclic indole derivatives through intramolecular imino Diels-Alder reaction of aminoanthraquinone with N-prenylated indole-2-carboxaldehydes in the presence of 20 mol % of triphenylphosphonium perchlorate (TPPP) is reported with extremely high cis selectivity in good yield.
17 citations
TL;DR: In this paper, the synthesis and metalation of cyclic silylphosphanyldisilane iPr4Si2(PH2)2 and cyclic polycyclic cyclic Silyl-phosphane tBu2Si(OSiiPr2) 2PSiMe3 with Me3SiCl was described.
Abstract: Synthesis and Metalation of the Diphosphanyldisilane iPr4Si2(PH2)2, of the cyclic Silylphosphane (iPr2Si)3PH as well as of the cyclic Siloxylphosphane tBu2Si(OSiiPr2)2PH
The 1,2-diphosphanyldisilane iPr4Si2(PH2)2 (1) was obtained from the reaction of iPr4Si2Cl2 with [Li(dme)PH2]. Whereas reactions of [Li(dme)PH2] with the 1,3-dichlortrisilane iPr6Si3Cl2 and the 1,5-dichlortrisiloxane tBu2Si(OSiiPr2Cl)2 yield the cyclic compounds (iPr2Si)3PH (2) and tBu2Si(OSiiPr2)2PH (3). The reaction of 1 with AlEt3 produced the polycyclic compound [iPr4Si2{P(H)AlEt2}{PAlEt}]2 (4), by reactions of 2 and 3 with nBuLi the tricyclic compounds [(iPr2Si)3PLi(dme)]2 (5) and [tBu2Si(OSiiPr2)2PLi(Et2O)]2·C7H8 (7) were obtained. Reactions of these lithium compounds with Me3SiCl produced the tertiary, cyclic silylphosphanes (iPr2Si)3PSiMe3 (6) and tBu2Si(OSiiPr2)2PSiMe3 (8).
13 citations
TL;DR: On exposure of these alcohols to thionyl chloride, cascade cyclization reactions occurred to furnish polycyclic compounds 13, 15, and 18 in a single operation.
Abstract: Condensation between truxenone (8) and the lithium acetylide derived from 0.9, 2.5, and 5.0 equiv of 1-ethynyl-2-(phenylethynyl)benzene produced the corresponding benzannulated enediynyl alcohol 9, diol 14, and triol 16, respectively. On exposure of these alcohols to thionyl chloride, cascade cyclization reactions occurred to furnish polycyclic compounds 13, 15, and 18 in a single operation. The unusual architectures of these polycyclic compounds were established by NMR spectroscopy and X-ray structure analyses.
2 citations
TL;DR: The appropriately substituted 5-O-tosyl derivative (1), easily prepared from 1,2- O-isopropylidene-alpha-d-xylofuranose, serves as a useful precursor for the preparation of highly condensed cyclic carbohydrates.
Abstract: The appropriately substituted 5-O-tosyl derivative (1), easily prepared from 1,2-O-isopropylidene-α-d-xylofuranose, serves as a useful precursor for the preparation of highly condensed cyclic carbohydrates. The synthesis involves a first cyclization of the 5-O-tosyl sugar derivative 1 to a highly reactive cyclic enamine, which subsequently undergoes the nucleophilic attack of a bifunctional reagent X(CH2)nZ in a regio- and stereospecific way. Finally, a spontaneous cyclization step allows the formation of a stereochemically defined extra ring, fused to the sugar backbone. The functionalization and size of this ring can be varied by the proper choice of the bifunctional reagent. X-ray diffraction analysis and intensive NMR studies with one of these carbohydrates were performed to highlight the strained nature of these compounds.
2 citations
Patent•
25 Oct 2007
TL;DR: In this article, an organic luminous element is characterized by comprising a halogenated condensed polycyclic compound emitting phosphorescence at a temperature in a temperature range of -20°C to 60°C.
Abstract: PROBLEM TO BE SOLVED: To provide a new phosphorescence-emitting, organic luminous compound, and to provide an organic luminous element using the same. SOLUTION: This organic luminous compound is characterized by comprising a halogenated condensed polycyclic compound emitting phosphorescence at a temperature in a temperature range of -20°C to 60°C. The halogenated condensed polycyclic compound comprises a condensed polycyclic compound comprising three or more benzene rings and having two or more halogen atoms. An organic luminous element having at least one organic compound-containing layer between a pair of electrodes is characterized in that at least one layer contains an organic luminous compound. It is preferable that the layer containing the organic luminous compound is a luminous layer. COPYRIGHT: (C)2008,JPO&INPIT
1 citations
Patent•
17 May 2007
TL;DR: A birefringent film with an optical indicatrix satisfying the following relationship: nz > nx =ny and which comprises at least one polycyclic compound having a -COOM group is disclosed in this paper.
Abstract: Disclosed is a birefringent film which has an optical indicatrix satisfying the following relationship: nz > nx =ny and which comprises at least one polycyclic compound having a -COOM group [wherein M represents a counter ion]. The polycyclic compound may be an acenaphtho[1,2-b]quinoxaline derivative represented by the general formula (I). The birefringent film shows a high refractive index in the thickness-wise direction and can be made into a thin film, because the polycyclic compound is contained in the film.
Patent•
20 Dec 2007
TL;DR: In this paper, a method for synthesizing a polycyclic compound from Anthraquinone derivatives with low reactivity is proposed. But the method is not suitable for the case of high pressure.
Abstract: PROBLEM TO BE SOLVED: To provide a method by which anthraquinone derivatives having low reactivity are mutually and directly subjected to ring condensation by dimerization and a polycyclic compound can stereoselectively be mass-produced in good yield. SOLUTION: The method for producing the condensed polycyclic compound is carried out as follows. Anthraquinones in which the 1-, 2-, 7- and 8-positions may be unsubstituted and the 3- and 6-positions are substituted with a free hydroxy group or substituted with a hydroxy group protected by a protecting group with the unsubstituted 4- and 5-positions are exposed to high pressure of 1×10 8 to 1×10 10 Pa. Two molecules thereof are mutually bound with carbon atoms at the 10-position and carbon atoms of either one of the 4- and 5-positions to provide a dimer. COPYRIGHT: (C)2008,JPO&INPIT
TL;DR: In this article, the enthalpies of formation for various Lewis acid complexes with representative unsaturated compounds (aldehydes, imines, alkynes, and alkenes) provide a means to evaluate the applicability of a particular catalyst in a catalytic reaction.
Abstract: Computed enthalpies of formation for various Lewis acid complexes with representative unsaturated compounds (aldehydes, imines, alkynes, and alkenes) provide a means to evaluate the applicability of a particular catalyst in a catalytic reaction. As expected, main group Lewis acids such as BX3 show much stronger complexes with heteroatoms than with carbon−carbon multiple bonds (σ-electrophilic Lewis acids). Gold(I) and copper(I) salts with non-nucleophilic anions increase the relative strength of coordination to the carbon−carbon multiple bonds (π-electrophilic Lewis acids). As representative examples for the use of σ-electrophilic Lewis acids in organic synthesis, the Lewis acid mediated allylation reactions of aldehydes and imines with allylic organometallic reagents which give the corresponding homoallyl alcohols and amines, respectively, are mentioned. The allylation method is applied for the synthesis of polycyclic ether marine natural products, such as hemibrevetoxin B, gambierol, and brevetoxin B. A...