Complete transligation of (AcO)4Rh2 applied onto λ-Al2O3 with 4-ethyl-2,6,7-trioxa-1-phosphabicyclo[2.2.2]octane

Complete transligation of (AcO)₄Rh₂ with 4-ethyl-2,6,7-trioxa-1-phosphabicyclo[2.2.2]octane was conducted in the solid phase on λ-Al₂O₃. The reduction of Rh¹¹ to Rh^I on λ-Al₂O₃ at 130°C under the actionof the above-mentioned bicyclic phosphite is accompanied by the oxidation of the acetate anion to the acetoxyl radical. The oxidation products were detected by IR and ESR spectroscopy. 2,6-Di-tert-butyl-4-methylphenol was used as a “spin trap” to identify stable secondary radical cations. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 2036–2038, October, 1998.     

X-ray structural study of 1-oxo-4-isopropyl-and 1-thio-4-propyl-2,6,7-trioxa-1-phosphabicyclo [2.2.2] octanes

Institute of Physiologically Active Substances, Academy of Sciences of the USSR. Translated from Zhurnal Strukturnoi Khimii, Vol. 30, No. 3, pp. 108–113, May–June, 1989.     

Cationic polymerization of 1-phenyl-4-ethyl-2,6,7-trioxabicyclo[2.2.2]octane

Cationic polymerization of bicyclo ortho ester, 1-phenyl-4-ethyl-2,6,7-trioxabicyclo[2.2.2]octane, was carried out with Lewis acids and cation sources to obtain the polyether containing ester group in the side chain. It was found that boron trifluoride etherate was the most active initiator in the Lewis acids. Magnesium perchlorate and triphenylcarbenium tetrafluoroborate, which have lower nucleophilic counter ions, initiated effectively the polymerization of bicyclo ortho ester.     

双环笼状磷酸酯衍生物的研究Ⅵ:4-取代-2,6,7-三氧杂-1-磷杂双环[2.2.2]辛烷的反应研究

双环笼状亚磷酸酯类衍生物由于其笼状结构所引起的张力及高位阻性 ,使得它同一般直链亚磷酸酯类化合物相比,在亲核取代反应性等方面有关明显的不同.本文用化合物1分别同SO~2Cl~2,Cl~2, Br~2, PCl~5等反应,结果表明,1均发生了类Arbuzov反应,生成具有相同立体构型的开环产物.本文还对化合物2的磷酰化反应进行了研究,发现在这类高位阻性的双环笼状亚磷酸酯衍生物的磷酰化反应中,DMAP是一个较有效的催化剂.     

Electron impact induced fragmentation of 4-alkyl derivatives of 2,6,7-trioxa-1-phosphabicyclo[2.2.2]octane and the corresponding 1-oxides, 1-sulfides and 1-selenides

The electron impact fragmentations of several derivatives of 2,6,7-trioxa-1-phosphabicyclo[2.2.2]octane have been examined by means of high resolution and metastable ion analysis. The principal fragmentation route for bicyclophosphites, phosphates and phosphorothionates involves a loss of formaldehyde, followed by a loss of the PO₂X and HPO₂X groups (X = -, O, S). The behaviour of phosphoroselenates is quite different, due partly to the favoured loss of selenium from the molecular ion before further fragmentation. Fragmentation through C? O bond breaking and a rearranged molecular ion is dependent on the exocyclic chalcogen atom (-, O, S, Se) on phosphorus. The reactions have been rationalized in terms of 1- and 4-substitutions.     

Organic reactions catalyzed by 1, 4-diazabicyclo [2.2.2] octane (DABCO)

The organic reactions catalyzed by 1, 4-diazabicyclo [2.2.2] octane (DABCO) are reviewed. Most of the reactions start conveniently from available substrate and proceed under mild conditions. The reactions are environmentally friendly and the catalyst can be recycled in some cases. The perspectives on DABCO-catalyzed reactions are pointed out. __________ Translated from Chemistry online, 2007, 70(10): 759–765 [译自: 化学通报]     

Transition Metal Complexes with Bidentate Ligands Spanning trans-Positions. VIII. The reactions of the nucleophile trans-[RuCl(NO)(1)] (1 = 2,11-bis(diphenylphosphinomethyl)benzo[c]-phenanthrene) with carbon monoxide and the phosphite ligand (2) (2 = 1-ethyl-3,5,8-trioxa-4-phosphabicyclo (2.2.2)octane)

The preparation of the nucleophile trans-[RuCl(NO)( 1 )], where 1 is the bidentate ligand Ph₂PCH₂C₁₈CH₂PPh₂, and of the five-coordinate species [RuCl(CO)(NO)( 1 )], [RuCl(CO)(NO)(Ph₂PCH₂Ph)₂] and [RuCl(NO)( 2 )( 1 )] are reported. The crystal structure of [RuCl(CO)(NO)( 1 )] shows that the coordination around the metal atom is distorted trigonal bipyramidal with the phosphorus atoms in axial positions. The Ru? N? O bond angle is 142.8°. ¹H- and ³¹P-NMR. and \documentclass{article}\pagestyle{empty}\begin{document}$ \tilde \nu $\end{document}_NO IR.-data for the above complexes are reported and related to the coordination geometry.     

1,4-二氮杂双环[2.2.2]辛烷催化的有机化学反应

综述了有机小分子催化剂1,4-二氮杂双环[2.2.2]辛烷(DABCO)在有机合成反应中的应用与发展。这种有机小分子催化的反应大多数条件温和、操作简单;相对过渡金属而言,对环境友好;在一定条件下,这种催化剂可以回收再利用。     

Nonvolatile Me(3)P-like P-donor ligand: synthesis and properties of 4-phenyl-1-phospha-4-silabicyclo[2.2.2]octane

[reaction: see text] A new trialkylphosphine ligand with Me(3)P-like steric and electronic properties, 4-phenyl-1-phospha-4-silabicyclo[2.2.2]octane (Ph-SMAP), was synthesized. Given a phenyl group at the silicon atom, the Ph-SMAP ligand displayed nonvolatility with retention of Me(3)P-like properties. The new ligand was air-stable, crystalline, and easy to handle.     

Polyfluorobicyclo[2.2.2]octanes-I 1H-tridecafluorobicyclo[2.2.2]octane,and some derived compounds

A Diels-Alder reaction between 1H-heptafluorocyclohexa-1,3-diene and methyl acrylate gave two carbomethoxy heptafluorobicyclo[2.2.2]oct-5-enes. Cobaltic fluoride fluorination of each isomer in the vapour phase gave a complex mixture containing tetradecafluorobicyclo[2.2.2]octane (3%), 1H-tridecafluorobicyclo[2.2.2]octane (30%), a mixture of 1H,2H- and 1H,3H-dodecafluorobicyclo[2.2.2]octanes (25%) and a liquid mixture of fragmentation products (40%). The formation of a perfluorocarbanion from 1H-tridecafluorobicyclo[2.2.2]octane has been demonstrated by isotopic exchange in aqueous potassium hydroxide. Lithium tridecafluorobicyclo[2.2.2]octyl has been formed using methyl lithium in ether at − 50° and reacted with deuterium oxide, methyl iodide and iodine to give the 1-deutero-, 1-methyl- and 1-iodo-tridecafluorobicyclo[2.2.2]octanes; it was unchanged after 1 hr at 35° and hence represents the most stable perfluoro alkyl lithium so far prepared.     

Synthesis of 2-(pyridin-3-yl)-1-azabicyclo[3.2.2]nonane, 2-(pyridin-3-yl)-1-azabicyclo[2.2.2]octane, and 2-(pyridin-3-yl)-1-azabicyclo[3.2.1]octane, a class of potent nicotinic acetylcholine receptor-ligands

In an attempt to generate nicotinic acetylcholine receptor (nAChR) ligands selective for the alpha4beta2 and alpha7 subtype receptors we designed and synthesized constrained versions of anabasine, a naturally occurring nAChR ligand. 2-(Pyridin-3-yl)-1-azabicyclo[2.2.2]octane, 2-(pyridin-3-yl)-1-azabicyclo[3.2.2]nonane, and several of their derivatives have been synthesized in both an enantioselective and a racemic manner utilizing the same basic synthetic approach. For the racemic synthesis, alkylation of N-(diphenylmethylene)-1-(pyridin-3-yl)methanamine with the appropriate bromoalkyltetrahydropyran gave intermediates which were readily elaborated into 2-(pyridin-3-yl)-1-azabicyclo[2.2.2]octane and 2-(pyridin-3-yl)-1-azabicyclo[3.2.2]nonane via a ring opening/aminocyclization sequence. An alternate synthesis of 2-(pyridin-3-yl)-1-azabicyclo[3.2.2]nonane via the alkylation of N-(1-(pyridin-3-ylethylidene)propan-2-amine has also been achieved. The enantioselective syntheses followed the same general scheme, but utilized imines derived from (+)- and (-)-2-hydroxy-3-pinanone. Chiral HPLC shows that the desired compounds were synthesized in >99.5% ee. X-ray crystallography was subsequently used to unambiguously characterize these stereochemically pure nAChR ligands. All compounds synthesized exhibited high affinity for the alpha4beta2 nAChR subtype ( K i < or = 0.5-15 nM), a subset bound with high affinity for the alpha7 receptor subtype ( K i < or = 110 nM), selectivity over the alpha3beta4 (ganglion) receptor subtype was seen within the 2-(pyridin-3-yl)-1-azabicyclo[2.2.2]octane series and for the muscle (alpha1betagammadelta) subtype in the 2-(pyridin-3-yl)-1-azabicyclo[3.2.2]nonane series.