Nitrogen diiodide

Novel synthetic procedures for indolizidine alkaloids were developed via a samarium diiodide-promoted carbon-nitrogen bond cleavage as a key step. Application of the procedure led to the total synthesis of (+)-(8R, 8aR)-perhydro-8-indolizidinol <2006H193>. 

Reduction of diaryltellurium dichlorides with samarium diiodide (typical procedure). Diaryl tellurium dichloride (1 mmol) was added to the deep blue solution of Sml2 (2.2 mmol) in THF (22 mL) at room temperature under nitrogen with stirring. The deep blue colour of the solution disappeared immediately and became yellow. The resulting solution was stirred at room temperature under nitrogen for 30 min. To the solution was added dilute hydrochloric acid, and the mixture was extracted with ether. The ethereal solution was washed with brine and dried over MgS04. The solvent was evaporated in vacuo, and the residue was purified by preparative TLC on silica gel (petroleum ether-methylene dichloride as eluent). 

C-Dihydrotoxiferine I chloride, C-tolKsN +Cl, [a]D —600° (1 1 aqueous alcohol), has two N-methyl groups attached at the quaternary Nb nitrogen atoms (39). Molecular distillation of the alkaloid chloride gives nordihydrotoxiferine with loss of methyl chloride this ditertiary base can be converted back into the bisquatemary alkaloid, as the diiodide, by methylation with methyl iodide (39). Dehydrogenation of C-dihydrotoxiferine I with sulfur or with zinc dust gives isoquinoline... 

The purple diiodide, [(//-C5H5)Mo(NO)l2]2, is stable in air for very long periods, but the brown dibromide and, especially, the orange dichloride have very limited stability toward aerial decomposition. The dibromide can be stored for several months under nitrogen at low temperatures. 

Cesium fluoride, CsF Sodium iodide, Nal Nitrogen trichloride, NClg Selenium diiodide, SeL... 

The iron is oxidized to the trivalent state, yet the complex is obtained as the diiodide. The proposed explanation is that the ligand is coordinated as a univalent anion a proton is removed from the amine nitrogen trans to the pyridine ring to relieve strain in the chelate ring. 

A new technique (applicable also for [3.2.1]propellane (71), cf. Ref. 57) has been developed using gas phase dehalogenation of the bridgehead diiodide with alkali metal vapor and leading to the corresponding propellane. This is then followed by trapping in an inert gas matrix (Ar). The heretofore unknown [2.2.1]propellane (80) was prepared, accompanied by norbornane. The potassium vapor is diluted with a sonicated stream of nitrogen. 

Pyrazolin-5-ones react with salts of various metals to form compounds in which the pyrazolinone has reacted in its enolic form with replacement of the enolic hydrogen to give a salt and having semipolar bonds formed by donation of electrons to the metal by the nitrogen atoms393 394 Usually these compounds contain the number of pyrazolinone residues corresponding to the valence of the metal atom. Such salts as cuprous iodide, ferric iodide, cobaltous iodide, silver iodide and silver diiodide participate in such reactions.393,394 In addition, complexes may be formed in which there has been no elimination of a small molecule between the reactants and no formation of ionic bonds.432... 

Reductive deamination of pyrrolidine (3) with samarium diiodide in THF-HMPA in the presence of methanol as the proton source yielded the desired piperidone (4) stereoselectively in 90% yield (Eq. (2)), where a carbon-nitrogen bond cleavage reaction and subsequent recyclization took place simultaneously (05TL5161). 

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