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Change of the Reaction Pattern by Methodological Variations in a Multicomponent Assembly Promoted by Ni Complexes
Author(s) -
GarcíaGómez Gabriel,
M. Moretó Josep
Publication year - 2001
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/1521-3765(20010401)7:7<1503::aid-chem1503>3.0.co;2-9
Subject(s) - chemistry , ketone , acetylene , vinyl chloride , double bond , trimethylsilyl , triple bond , regioselectivity , quenching (fluorescence) , vinyl ether , moiety , enol ether , enol , nickel , medicinal chemistry , ether , methyl vinyl ketone , organic chemistry , polymer chemistry , catalysis , fluorescence , physics , quantum mechanics , copolymer , polymer
Abstract The π‐allylnickel complex formed by the addition of trimethylsilyl chloride (TMSCl) to a mixture of [Ni(cod) 2 ] (cod=1,5‐cyclooctadiene) and a vinyl ketone (Mackenzie complex) carbometalates an acetylene in a completely regioselective manner resulting in the formation of the corresponding vinyl nickel species. This intermediate is capable of controlled quenching in a variety of ways to give different types of compounds: under a CO atmosphere, an acylnickel species is formed that ensues from the carbometalation of the enol ether double bond to form cyclopentenone derivatives. Alternatively, if acetylene is present in excess and CO is absent, another acetylene moiety will replace the CO and cyclohexadienes will result instead. Finally, if only an excess of the vinyl ketone is used, the product from a slow double addition of the vinyl ketone across the triple bond is formed. The regioselectivities obtained by the present method are different from those obtained by the involvement of nickel acyclopentadienes as intermediates when the order of addition is reversed.