Table 1.
Ruthenium-catalyzed [4+2] cycloaddition of benzocyclobutenones 7a-h with α-ketols 12a-g.a
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Yields of material isolated by silica gel chromatography. Enantioselectivities were determined by chiral stationary-phase HPLC analysis. Diastereoselectivities were determined by 1H NMR analysis of crude reaction mixtures.
Diol (200 mol%).
Ru3(CO)12 (10 mol%), (R)-DM-SEGPHOS (30 mol%), 140 °C, 48 hr.
Ru3(CO)12 (3.3 mol%), (R)-DM-SEGPHOS (10 mol%), 140 °C. ND = Not determined. See Supporting Information for further details.