The Reaction Op Brcmoacetil Bromide with Selected Orgahometallic Compounds
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Date
1980-06
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Addis Ababa Universty
Abstract
Organometallic compounds are widely used as heterogenous and homogenous catalysts in the industrial productions of important chemicals and synthetic products. In many cases of such industrial transformation, metal carbenes are thought to play important roles as the active catalytic ingredients that bring about the transformation. Such carbenes
are classified into two groups electrophilic and nucleophilic. Although several nucleophilic carbenes have been prepared, no general synthetic methods have been developed for the generation of electrophilic metal carbenes. We believe that oe-monohaloalkyltransition
metal derivatives can be used as precursors of electrophilic metal carbenes via their interaction with lewis acids(see equation below)<. Por example, the interactions of a-monolialcalkyltransition metal derivatives with Lewis acids may produce metal
carbenes capable of catalyzing the olefin metathesis reactions.
LnMCR2Cl + A1C15-* —> fLnMCCRg)]A1C14
R = alkyl, H, aryl; In = Ligand.
Consequently, our main goal is to synthesize
a-monohaloalkyltransition metal derivatives by thermal or photochemical decompositions of the
haloacetyl metal derivatives.
BrCH2COM(00)^0^ with traces of BrC0CH2M(CCO^C^H^ (M = Mo , V/) were made in good yields by allowing
NaM(CO)5C5H^(M = Mo , W) to react with BrCH2G0Br.
The thermal decompositions of BrCH2C0M(C0)^ Cc,H^(M = Mo , W) were shown to involve p-halogen
elimination. Decarbonylation followed by further 1
decomposition produced the metal halides,
G^H^M(C0)^Br (M =- Mo , W)
The photochemical decompositions of BrCH2C0M(C0)
(M - Mo , W) gave the metal halides ,
C^H^M(CO)jBr (M = Mo, V/). Also trace amounts of
B r C H2M(C0) (M = Mo , w) were obtained.
Na5'e(C0)2CrH^ reacted with BrCH2C0Br giving
[C^H^FeCOOIg]^ as the major product. Also small
quantities of BrCHgCOFeCCO)^!^ and BrCOCHgFeCCO^C^ were detected. (Ph^P)^Pt reacted with BrCH2C0Br
giving Br(BrCH2C0)(Ph^P)2Pt and trace quantity of
Br(BrC0CH2)(Ph^P)2Pt. The thermal and photochemical
decomposition of Br(BrCH2C0)(Ph^P)2Pt resulted in
the production of (Ph^P)2Pt Br2>
Description
Keywords
Organometallic Compounds