Diversity‐Oriented Approach to Carbocycles and Heterocycles through Ring‐Rearrangement Metathesis, Fischer Indole Cyclization, and Diels–Alder Reaction as Key Steps

Abstract

Readily available dicyclopentadiene derivatives were subjected to ring‐rearrangement metathesis in the presence of ruthenium catalysts to deliver a range of fused polycycle frameworks containing carbocycles, oxacycles, and azacycles. We have used atom‐economic processes such as ring‐rearrangement metathesis, Fischer indole cyclization, and the Diels–Alder reaction as key steps.

Design and synthesis of fused polycycles via Diels–Alder reaction and ring-rearrangement metathesis as key steps

“…Analogously as described in [ 2 ], to a stirred solution of diketone 3 (0.2 g, 0.83 mmol) in dry THF (10 mL) was added allylmagnesium bromide (4.2 mL, 1 M solution in ether) at 0 °C under nitrogen atmosphere, and the reaction mixture was stirred for 5 h at rt. After completion of the reaction (TLC monitoring), the reaction mixture was quenched with saturated ammonium chloride and extracted with ethyl acetate.…”

“…Analogously as described in [ 2 ], to a suspension of NaH (115 mg, 4.77 mmol) in dry DMF (10 mL), was added a solution of compound 9 (240 mg, 0.68 mmol) in DMF (10 mL) and allyl bromide (0.33 g, 2.72 mmol) at 0 °C under nitrogen atmosphere and stirred at rt for 1 h. After completion of the reaction (TLC monitoring), the reaction mixture was quenched with saturated ammonium chloride and extracted with ethyl acetate. The combined organic layer was washed with water, brine and dried over sodium sulfate.…”

“…Analogously as described in [ 2 ], to a stirred solution of compound 5 (40 mg, 0.11 mmol) in toluene (40 mL) degassed with nitrogen for 10 minutes, purged with ethylene gas for another 10 minutes and then G-II catalyst (8 mg, 10 mol %) was added and stirred at 70 °C for 12 h under ethylene atmosphere. After completion of the reaction (TLC monitoring), the solvent was removed on a rotavapor under reduced pressure and purified by silica gel column chromatography by eluting with 5–10% ethyl acetate in petroleum ether provided 6a and 6b as a colourless liquids (25 mg and 10 mg, 70% and 28%, respectively).…”

Application of Fischer Indolization under Green Conditions using Deep Eutectic Solvents

“…A readily available dicyclopentadiene derivative 31 in the presence eutectic melt L‐(+)‐TA:DMU was converted to indole derivative 32 (79 %), which on further allylation followed by ring‐rearrangement metathesis (RRM) with the aid of G‐II catalyst gave indole‐fused polycyclic framework 33 . This indole derivative is generated by two atom‐economic reactions [40] such as FI and RRM as key steps (Scheme ).…”

The chemistry of the carbon-transition metal double and triple bond: Annual survey covering the year 2014

“…Several tricyclic dicyclopentadiene derivatives (e.g. 318) were subjected to RRM, including the conversion of enone 318 to tricyclic compound 319 [835].…”