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Palladium‐Induced Intramolecular Pyridine‐Allyl Coupling Reactions: Formation of N‐Bridgehead Heterocycles with a Stable C–N Bond
Author(s) -
Chengebroyen Jaganaiden,
Grellier Mary,
Pfeffer Michel
Publication year - 1998
Publication title -
european journal of inorganic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.667
H-Index - 136
eISSN - 1099-0682
pISSN - 1434-1948
DOI - 10.1002/(sici)1099-0682(199810)1998:10<1563::aid-ejic1563>3.0.co;2-p
Subject(s) - chemistry , palladium , medicinal chemistry , pyridine , intramolecular force , regioselectivity , acetonitrile , chloride , yield (engineering) , stereochemistry , organic chemistry , catalysis , materials science , metallurgy
In the presence of stoichiometric amounts of bis(acetonitrile)dichloropalladium(II) the ortho ‐alkenylpyridines 2‐but‐3′‐en‐1′‐ylpyridine ( 1 ), 2‐pent‐5′‐en‐1′‐ylpyridine ( 2 ), 2‐hex‐5′‐en‐1′‐ylpyridine ( 3 ), 2‐hept‐6′‐en‐1′‐ylpyridine ( 4 ) and 2‐methyl‐6‐pent‐4′‐en‐1′‐ylpyridine ( 5 ) led to a mixture of coordination compounds such as 2‐alken‐1′‐ylpyridine‐ĸ N :ĸ 2 C ‐dichloropalladium(II) and bis(2‐alken‐1′‐ylpyridine‐ĸ N )‐dichloropalladium(II) together with 2‐pent‐4‐ene‐1′,3′‐diylpyridine‐ĸ N :ĸ 3 C ‐chloropalladium(II) and 2‐hex‐4‐en‐1′,3′‐diylpyridine‐ĸ N :ĸ 3 C ‐chloropalladium(II) in the case of 2 and 3 respectively. The latter were quantitatively demetallated in the presence of an excess of triphenylphosphane to yield tris(triphenylphosphane)palladium(0), 2‐vinyl‐2,3‐dihydroindolizinium chloride and 2‐prop‐1′‐en‐1′‐yl‐2,3‐dihydroindolizinium chloride, respectively, by a regioselective addition of the pyridine unit onto the more congested terminal carbon atom of the allyl fragment.