Synthesis of Hexahydro-1H-isoindole Derivatives from Arylacyl Bromides via Homoallenic Bromohydrins
摘要:
A procedure has been developed for the concise synthesis of hexahydro-H-1-isoindole derivatives starting from phenacyl bromides. The approach employs a sequence involving an initial indium-mediated allenylation reaction of an arylacyl bromide with propargyl bromide. This process is followed by FeBr3-mediated S(N)2'-type substitution reaction of the formed homoallenic bromohydrin to produce a 2,5-dibromo-4-aryl-1,3-pentadiene, which then is subjected to a sequential, one-pot N-alkylation reaction with N-allyl-N-(p-tosyl)amine and a highly diastereoselective intramolecular DielsAlder reaction of the formed ene-diene to generate the target hexahydro-H-1-isoindole.