Heck reaction indolizidines

Sato, Y., Nukui, S., Sodeoka, M. and Shibasaki, M. 1994. Asymmetric Heck reaction of alkenyl iodides in tbe presence of silver salts. Catalytic asymmetric synthesis of decalin and functionalized indolizidine derivatives. Tetrahedron 50 371-382. 

For an intramolecular asymmetric Heck-type reaction of alkenyl iodide 73 to form an optically active indolizidine derivative, a palladium catalyst coordinated... 

Similar results have been observed for the arylation of indoUzidine 53, which occurs at C-3 to give 54 (Scheme 11.19) [64]. Attempts to trap a possible Heck intermediate in this reaction using indolizidine 55 as the substrate (via 57 and 58) failed, and led only to a mixture of 56a and 56b. For this, and for the palladium-catalyzed alkynylation of related heterocycles with alkynylbromides [65], an elec-trophihc aromatic substitution was proposed. A Heck process was also excluded in the paUadium-catalyzed arylation of imidazolidones, a reaction for which an intramolecular isotope effect of ku/kj) = 4.5 was found [66]. 

For their formal synthesis of (5E,9Z)-(+)-indolizidine 223AB ent 1780), Sulikowski and his team devised an interesting intramolecular Heck cyclization of the enamide 1791, which was promoted by a palladiu-m(II)-(R)-BINAP complex with silver phosphate as haHde scavenger (Scheme 226). When performed in dimethylformamide as solvent, the reaction produced the (R)-(+)-8,8a-dihydroindoUzin-3(7H)-one 1792 in 64% yield and an ee of 85%. Reduction of the conjugated alkene followed by treatment with methanol in trifluoroacetic acid produced the... 

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