Preparation and reactions of some orthomanganated ketones, amides and aldehydes
type: CreativeWork
description: η²-(1-acetyl-2-indolyl)tetracarbonylmanganese (7, R=CH₃) and η²-(2-N,N- dimethylamidophenyl)tetracarbonylmanganese (13), the first examples of orthomanganated amides, have been synthesized by reaction of N-acetylindole and N,N-dimethylbenzamide respectively with PhCH₂Mn(CO)₅. 7 (R=CH₃) was identified by X-ray crystallography. Preparation of the N-benzoyl- (7, R=Ph) analogue highlights a preference for metalation at the 5-membered indolyl ring, rather than the benzoyl ring. The N-benzoylpyrrole analogue of 7, η²-(1-benzoyl-2-pyrrolyl)tetracarbonylmanganese (4) was also prepared. Orthomanganated N,N-dimethylbenzamide (13) showed only oxygen donation to manganese, despite the presence of a possible nitrogen donor. N,N-diethyl and N,N-pyrrolidinyl analogues of 13 behaved similarly. [diagram] (7) [diagram] (13) η²-(2-formyl-5-dimethylaminophenyl)tetracarbonylmanganese (21) and its 5-methoxy analogue were prepared similarly and are the first examples of orthomanganated aldehydes. 2-thiophenecarboxaldehyde and 3-thiophenecarboxaldehyde gave analogous 3-metalated and 2-metalated aldehyde products. Two new dimetalated arenes, η²,η²-(2,4-diacetylphenyl)bis-1,5- (tetracarbonyl)manganese (25) and η²,η²-(2,5-diacetylphenyl)bis-1,4-(tetracarbonyl)manganese (27), have been identified, in the former case by crystal structure analysis. The first examples of coupling reactions of orthomanganated carbonyl compounds with alkynes are reported that do not require a palladium(II) catalyst: η²-(2-acetylphenyl)tetracarbonylmanganese (39) was treated with diphenylacetylene to give in good yield 1-methyl-2,3-diphenylinden-1-ol (40), the structure of which was determined crystallographically. Acetylene, 4-octyne and bis(trimethylsilyl)-acetylene reacted similarly. For indenols arising from coupling with the unsymmetric alkynes phenylacetylene and trimethylsilylacetylene, the alkyne substituent occupied the 2-position in the final product. A possible mechanism for the couplings is discussed. [D…
abstract: η²-(1-acetyl-2-indolyl)tetracarbonylmanganese (7, R=CH₃) and η²-(2-N,N- dimethylamidophenyl)tetracarbonylmanganese (13), the first examples of orthomanganated amides, have been synthesized by reaction of N-acetylindole and N,N-dimethylbenzamide respectively with PhCH₂Mn(CO)₅. 7 (R=CH₃) was identified by X-ray crystallography. Preparation of the N-benzoyl- (7, R=Ph) analogue highlights a preference for metalation at the 5-membered indolyl ring, rather than the benzoyl ring. The N-benzoylpyrrole analogue of 7, η²-(1-benzoyl-2-pyrrolyl)tetracarbonylmanganese (4) was also prepared. Orthomanganated N,N-dimethylbenzamide (13) showed only oxygen donation to manganese, despite the presence of a possible nitrogen donor. N,N-diethyl and N,N-pyrrolidinyl analogues of 13 behaved similarly. [diagram] (7) [diagram] (13) η²-(2-formyl-5-dimethylaminophenyl)tetracarbonylmanganese (21) and its 5-methoxy analogue were prepared similarly and are the first examples of orthomanganated aldehydes. 2-thiophenecarboxaldehyde and 3-thiophenecarboxaldehyde gave analogous 3-metalated and 2-metalated aldehyde products. Two new dimetalated arenes, η²,η²-(2,4-diacetylphenyl)bis-1,5- (tetracarbonyl)manganese (25) and η²,η²-(2,5-diacetylphenyl)bis-1,4-(tetracarbonyl)manganese (27), have been identified, in the former case by crystal structure analysis. The first examples of coupling reactions of orthomanganated carbonyl compounds with alkynes are reported that do not require a palladium(II) catalyst: η²-(2-acetylphenyl)tetracarbonylmanganese (39) was treated with diphenylacetylene to give in good yield 1-methyl-2,3-diphenylinden-1-ol (40), the structure of which was determined crystallographically. Acetylene, 4-octyne and bis(trimethylsilyl)-acetylene reacted similarly. For indenols arising from coupling with the unsymmetric alkynes phenylacetylene and trimethylsilylacetylene, the alkyne substituent occupied the 2-position in the final product. A possible mechanism for the couplings is discussed. [D…
author: Robinson, Nicholas P.
license: https://researchcommons.waikato.ac.nz/bitstreams/25903149-d8aa-458a-a782-011f3ace10c4/download
date published: 1989
date modified: 2026-07-24T05:57:18Z
provider: University Waikato
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: The University of Waikato