A wide mechanistic spectrum observed in three different reactions with organometallic reagents
The halogen-lithium exchange reaction is of one of the most powerful method for the preparation of organolithium compounds, but its mechanism is still controversial. To afford some new elements, we synthesized a new suitable fast radical clock, bearing a phenyl group at the alkene C-terminal. The ex...
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paper:paper_08943230_v23_n10_p978_Rodriguez2023-06-08T15:47:46Z A wide mechanistic spectrum observed in three different reactions with organometallic reagents Vázquez, Alvaro Joaquín halogen-lithium exchange heteroaromatic organocuprates NO insertion TMSCl Addition products Complex mechanisms Functionalized compounds halogen-lithium exchange Halogen-lithium exchange reaction heteroaromatic organocuprates Lithium amide Nitrosonium NO insertion Organolithium compounds Organometallic reagent Phenyl group Radical clocks Reaction conditions Reactive species Theoretical calculations TMSCl Amides Halogen compounds Halogen elements Lead compounds Lithium Lithium compounds Olefins Organometallics Addition reactions The halogen-lithium exchange reaction is of one of the most powerful method for the preparation of organolithium compounds, but its mechanism is still controversial. To afford some new elements, we synthesized a new suitable fast radical clock, bearing a phenyl group at the alkene C-terminal. The examination of some mechanistic clues, as well as the identification of the unexpected by-products allowed the conclusion that the reaction proceeds by a polar mechanism and no evidence for radicals were found. The second reaction discussed is the insertion of NO in the N-Li bond of lithium amides. Evidence for the involving of paramagnetic and nitrosonium intermediates, as well as equilibria between different reactive species were essential for the proposal of a whole complex mechanism, which was confirmed by theoretical calculations. Finally, results on the addition of heteroaromatic organocuprates to a,b-unsaturated substrates are presented. Several reaction conditions were looked for to lead the reaction toward the more interesting 1,4-conjugated addition. Thus, addition of up to 6 equivalents of TMSCl to the reaction with arylcuprates leads to a clean addition yielding more than 95% of the 1,4-addition product. A further objective of the paper is to show how the search of unexpected routes of reaction allowed developing original pathways to lead them toward the formation of appealing functionalized compounds. Copyright © 2010 John Wiley and Sons, Ltd. Fil:Vázquez, A.J. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. 2010 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_08943230_v23_n10_p978_Rodriguez http://hdl.handle.net/20.500.12110/paper_08943230_v23_n10_p978_Rodriguez |
| institution |
Universidad de Buenos Aires |
| institution_str |
I-28 |
| repository_str |
R-134 |
| collection |
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) |
| topic |
halogen-lithium exchange heteroaromatic organocuprates NO insertion TMSCl Addition products Complex mechanisms Functionalized compounds halogen-lithium exchange Halogen-lithium exchange reaction heteroaromatic organocuprates Lithium amide Nitrosonium NO insertion Organolithium compounds Organometallic reagent Phenyl group Radical clocks Reaction conditions Reactive species Theoretical calculations TMSCl Amides Halogen compounds Halogen elements Lead compounds Lithium Lithium compounds Olefins Organometallics Addition reactions |
| spellingShingle |
halogen-lithium exchange heteroaromatic organocuprates NO insertion TMSCl Addition products Complex mechanisms Functionalized compounds halogen-lithium exchange Halogen-lithium exchange reaction heteroaromatic organocuprates Lithium amide Nitrosonium NO insertion Organolithium compounds Organometallic reagent Phenyl group Radical clocks Reaction conditions Reactive species Theoretical calculations TMSCl Amides Halogen compounds Halogen elements Lead compounds Lithium Lithium compounds Olefins Organometallics Addition reactions Vázquez, Alvaro Joaquín A wide mechanistic spectrum observed in three different reactions with organometallic reagents |
| topic_facet |
halogen-lithium exchange heteroaromatic organocuprates NO insertion TMSCl Addition products Complex mechanisms Functionalized compounds halogen-lithium exchange Halogen-lithium exchange reaction heteroaromatic organocuprates Lithium amide Nitrosonium NO insertion Organolithium compounds Organometallic reagent Phenyl group Radical clocks Reaction conditions Reactive species Theoretical calculations TMSCl Amides Halogen compounds Halogen elements Lead compounds Lithium Lithium compounds Olefins Organometallics Addition reactions |
| description |
The halogen-lithium exchange reaction is of one of the most powerful method for the preparation of organolithium compounds, but its mechanism is still controversial. To afford some new elements, we synthesized a new suitable fast radical clock, bearing a phenyl group at the alkene C-terminal. The examination of some mechanistic clues, as well as the identification of the unexpected by-products allowed the conclusion that the reaction proceeds by a polar mechanism and no evidence for radicals were found. The second reaction discussed is the insertion of NO in the N-Li bond of lithium amides. Evidence for the involving of paramagnetic and nitrosonium intermediates, as well as equilibria between different reactive species were essential for the proposal of a whole complex mechanism, which was confirmed by theoretical calculations. Finally, results on the addition of heteroaromatic organocuprates to a,b-unsaturated substrates are presented. Several reaction conditions were looked for to lead the reaction toward the more interesting 1,4-conjugated addition. Thus, addition of up to 6 equivalents of TMSCl to the reaction with arylcuprates leads to a clean addition yielding more than 95% of the 1,4-addition product. A further objective of the paper is to show how the search of unexpected routes of reaction allowed developing original pathways to lead them toward the formation of appealing functionalized compounds. Copyright © 2010 John Wiley and Sons, Ltd. |
| author |
Vázquez, Alvaro Joaquín |
| author_facet |
Vázquez, Alvaro Joaquín |
| author_sort |
Vázquez, Alvaro Joaquín |
| title |
A wide mechanistic spectrum observed in three different reactions with organometallic reagents |
| title_short |
A wide mechanistic spectrum observed in three different reactions with organometallic reagents |
| title_full |
A wide mechanistic spectrum observed in three different reactions with organometallic reagents |
| title_fullStr |
A wide mechanistic spectrum observed in three different reactions with organometallic reagents |
| title_full_unstemmed |
A wide mechanistic spectrum observed in three different reactions with organometallic reagents |
| title_sort |
wide mechanistic spectrum observed in three different reactions with organometallic reagents |
| publishDate |
2010 |
| url |
https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_08943230_v23_n10_p978_Rodriguez http://hdl.handle.net/20.500.12110/paper_08943230_v23_n10_p978_Rodriguez |
| work_keys_str_mv |
AT vazquezalvarojoaquin awidemechanisticspectrumobservedinthreedifferentreactionswithorganometallicreagents AT vazquezalvarojoaquin widemechanisticspectrumobservedinthreedifferentreactionswithorganometallicreagents |
| _version_ |
1768545056357089280 |