Date Available

12-14-2011

Year of Publication

2006

Document Type

Dissertation

College

Arts and Sciences

Department

Chemistry

First Advisor

John P. Selegue

Abstract

The synthesis, structure, and reactivity of some organometallic-fusedheterocycles were studied. This work was divided into three parts: first,thiapentalenyl tricarbonyl manganese complexes [Mn(CO)3{??5-SC7H3-1,3-(R)2}]were synthesized employing thiation on diacyl precursors; second, attempts toform the 5,5-fused ring pyrrole analogs to the thiapentalenyl complexes led to theformation of various amine and imine ligands and manganese complexes, but notthe desired ring-closed pyrroles; third, reductive amination on a ferrocenylmonoaldehyde substrate led to the formation of di(N-(ferrocenylmethyl))-Nmethylamineand its cyanoborane and cyanoborohydride analogs.Isolation of the desired thiapentalenyl manganese complexes wasaccomplished by first forming 1,2-diacylcyclopentadienes (fulvenes), convertingto the corresponding thallium salts [Tl{1,2-C5H3(COR)2}] employing thalliumethoxide, transmetallating with [Mn(CO)5Br], and ring closing using either P4S10or Lawesson's Reagent. Ring closure from the diacylmanganese complexes[Mn(CO)3{??5-1,2-C5H3(COR)2}] gave air stable thiapentalenyl complexes inmoderate to good yield and was tolerable to a variety of functional groups (aryl,arylacetyl, t-butyl). In the cases where 1,2-diarylacetyl complexes wereemployed, the isolated products were "quinoidal". While ring closure on thecorresponding diacylrhenium tricarbonyl complexes was not feasible, it wasobserved that these quinoidal thiapentalenyl structures could be formed on aruthenium Cp* moiety using the arylacetyl fulvenes.Various keto-amines or enol-imines could be formed from the 1,2-dibenzoyl fulvene employing primary amines (R = H, Me, OH, OMe). In thepresence of a reducing agent, neither reduction nor ring closure was observedfor any of the cases investigated. Formation of the corresponding manganesetricarbonyl complex for the methyoxyimine case was accomplished by reaction ofthe enol-methoxyimine with thallium ethoxide and then transmetallating with[Mn(CO)5Br]. Reaction of this keto-imine complex with various reducing agentsdid not lead to the desired 5,5-fused ring pyrrole complex but to reduction to thecorresponding alcohol.Diferrocenylmethyl methylamine complexes were obtained by reaction offerrocene monoaldehyde with ferrocenylmethyl methylamine in the presence of amild reducing agent (NaCNBH3). Isolation under anhydrous conditions gave theunexpected cyanoborohydride salt, di(N-(ferrocenylmethyl))-N-methylammoniumcyanoborohydride. Aqueous work-up gave the corresponding free amine.Conversion of the cyanoborohydride salt to the corresponding cyanoborane,di(N-(ferrocenylmethyl))-N-methylammonium–cyanoborane, was accomplishedby refluxing the cyanoborohydride salt in THF.

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