Alkylation, Insertion of Isocyanides, and Intramolecular Rearrangement Processes in Azatantalacyclopentene Complexes. X-ray Crystal Structure of [TaCpMe2(CHCHCMe2NAr-κ2 C,N)] (Cp = η5-C5Me5; Ar = 2,6-Me2C6H3)
Chloro methyl and dimethyl azatantalacyclopentene complexes [TaCp*Cl2 - x Me x (CHCHCMe2NAr-κ2 C,N)] (Cp* = η5-C5Me5; Ar = 2,6-Me2C6H3; x = 1, 2; 2, 3) can be prepared by reaction of [TaCp*Cl2(CHCHCMe2NAr-κ2 C,N)] (1a) with dimethylzinc and chloromethylmagnesium, respectively. Reaction of 1a with di...
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Published in | Organometallics Vol. 24; no. 14; pp. 3552 - 3560 |
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Main Authors | , , , |
Format | Journal Article |
Language | English |
Published |
American Chemical Society
04.07.2005
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Online Access | Get full text |
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Summary: | Chloro methyl and dimethyl azatantalacyclopentene complexes [TaCp*Cl2 - x Me x (CHCHCMe2NAr-κ2 C,N)] (Cp* = η5-C5Me5; Ar = 2,6-Me2C6H3; x = 1, 2; 2, 3) can be prepared by reaction of [TaCp*Cl2(CHCHCMe2NAr-κ2 C,N)] (1a) with dimethylzinc and chloromethylmagnesium, respectively. Reaction of 1a with dibenzylmagnesium leads to the monoalkylated complex [TaCp*Cl(CH2Ph)(CHCHCMe2NAr-κ2 C,N)] (4). The alkylation of [TaCp*Cl2{C(Ph)CHCMe2NAr-κ2 C,N}] (1b) with 2 equiv of chloromethylmagnesium at low temperature gave the dimethyl azatantalacyclopentene complex [TaCp*Me2{C(Ph)CHCMe2NAr-κ2 C,N}] (5), which at room temperature decomposes, giving the dimethyl(imido) complex [TaCp*Me2(NAr)] (7), identified by NMR spectroscopy. Alkylation of 1b with 0.5 equiv of dibenzylmagnesium leads to the monobenzyl complex [TaCp*Cl(CH2Ph){C(Ph)CHCMe2NAr-κ2 C,N}] (6); however treatment with 1 equiv of the alkylating reagent gave the dibenzyl(imido) [TaCp*(CH2Ph)2(NAr)] (8) in a mixture with 6 as minor component. Moreover, 1a reacts with 1 equiv of isocyanides RNC (R = 2,6-Me2C6H3; tBu) to give the dichloro(imido) complex [TaCp*Cl2(NAr)] (9), while the treatment of the chloro methyl azatantalacyclopentene 2 with 2 equiv of isocyanides RNC (R = 2,6-Me2C6H3; tBu) at different conditions affords the imido η2-iminoacyl derivatives [TaCp*Cl(NAr){η2-C(Me)NR}] (R = 2,6-Me2C6H3, 12; tBu, 13) in good yields with simultaneous elimination of s-trans-vinylazacumulenes R−NCCH−CHCMe2 (R = 2,6-Me2C6H3, 10; tBu, 11). Similarly, the reaction of the dimethyl azatantalacyclopentene 3 with 1 equiv of 2,6-Me2C6H3NC produces the alkenylamido imido methyl derivative [TaCp*Me(NAr){η1-N(Ar)-C(Me)CH−CHCMe2}] (14), which with one additional equivalent of isocyanide gives the imido η2-iminoacyl methyl compound [TaCp*Me(NAr)(η2-C{CH(CMeNAr)(CHCMe2)}NAr)] (15). All compounds were studied by IR and NMR spectroscopy, and the molecular structure of complex 3 was determined by X-ray diffraction methods. |
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Bibliography: | ark:/67375/TPS-SLJK6RK5-D This paper is dedicated to the memory of Dr. Juan Carlos del Amo, who was a victim of the March 11, 2004, tragedy in Madrid. istex:61E9DD9ACE9F69B8776614943733F523CEC43078 |
ISSN: | 0276-7333 1520-6041 |
DOI: | 10.1021/om050289z |