Dibenzoylmethane → (S)-2-(1-(4-Chlorophenyl)-2-nitroethyl)-1,3-diphenylpropane-1,3-dione

Participants

Reaction Conditions

Reaction Steps

To a solution of 1,3-diphenyl-1,3-propanedione (1a) (0.3 mmol, 3 eq) and 1-chloro-4-((E)-2-nitrovinyl)benzene (2g) (0.1 mmol, 1 eq) in diethyl ether (0.3 mL) was added catalyst VI (Q-NH2) (0.015 mmol, 0.15 eq). The resulting mixture was stirred at room temperature (23° C.). After the reaction was complete (monitored by TLC), the product 3g was isolated and purified by centrifuge/washing with diethyl ether (0.3 mL). All the catalyst VI (0.15 equiv) and 2 equivalents of the excess the dione 1a were retained in the filtrate. The combined ethereal filtrate was evaporated to 0.3 mL before the dione 1a (1 eq) and 2g (1 eq) were added again to the solution for the next round of the Michael reaction. This was to ensure that the reaction condition for each cycle was almost the same as the previous one. The excellent yields (96% in average) and enantioselectivities (98-94% ee) were achieved in seven cycles.

Provenance & Evidence