Selective hetero- and carbo-cycle syntheses via masked cyclopalladated secondary amine and ketone functions
| Autor: | E. Wehman, F. Maassarani, Michel Pfeffer, John Spencer |
|---|---|
| Rok vydání: | 1994 |
| Předmět: |
chemistry.chemical_classification
Nucleophilic addition Ketone Bicyclic molecule Stereochemistry Organic Chemistry Alkyne Regioselectivity Biochemistry Medicinal chemistry Inorganic Chemistry chemistry Electrophile Materials Chemistry Amine gas treating Physical and Theoretical Chemistry Chemoselectivity |
| Zdroj: | Journal of Organometallic Chemistry. 466:265-271 |
| ISSN: | 0022-328X |
| DOI: | 10.1016/0022-328x(94)88054-9 |
| Popis: | The iodo-bridged or cationic cyclopalladated complexes 1b and 1c derived from N -phenyl-2-pyridylamine and 4b derived from phenyl-2-pyridylketone reacted with internal alkynes to yield five-membered heterocyclic 3 and carbocyclic products 6 with high chemoselectivity. The indoles 3b – 3f , formed from 1b or 1c and disymmetric alkynes, were obtained regioselectively, suggesting that this reaction might be under both electronic and steric control. Analysis of the regiochemistry of this reaction has led us to propose a pathway involving a nucleophilic addition of the secondary amine function to an alkyne activated by η 2 - coordination to palladium. The indenol derivatives 6 , obtained as stable bis( O , N )-palladated chelates, result from the insertion of the alkyne into the Pd-C bond of 4b followed by attack of the palladated vinyl carbon atom on the electrophilic carbonyl function. In so far as their reactivities towards alkynes are concerned, 1b and 1c behave as masked cyclopalladated secondary amine functions and 4b as masked cyclopalladated ketone functions. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
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