Beilstein J. Org. Chem.2010,6, No. 48, doi:10.3762/bjoc.6.48
difluorodihydropyridinones via a ring-closing metathesis reaction, and of 4,4-difluoro-3-oxoisoquinolines through a ring-closing metathesis–enynemetathesis tandem reaction. These products, in turn, undergo a Diels–Alder reaction to yield heterotricyclic systems in moderate to good yields.
Keywords: bicyclic lactams
tricyclic ring systems [20].
Results and Discussion
Initially, we investigated the enynemetathesis reaction of fluorinated enyne 1a with commercially available ruthenium carbene complexes, the Hoveyda–Grubbs second-generation catalyst being the most reactive (entries 1–3, Table 1). The reaction at 110 °C
reaction time. The stereochemistry of 7a and 7b was determined by COSY and NOESY experiments.
Recently, various tandem reactions with ruthenium complexes have become popular in organic chemistry because Ru(II) complexes are capable of catalyzing additional reactions [26][27]. Since our enynemetathesis
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Graphical Abstract
Scheme 1:
Diels–Alder reaction of diene 2 with 4 and 6. aThe other isomers of 7a and 7b were isolated in 8% a...