ISSN:
0947-6539
Keywords:
organostannanes
;
palladium complexes
;
palladacycles
;
Stille reaction
;
transmetalation
;
Chemistry
;
General Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
A strategy based on a Stille cross-coupling reaction of organostannanes interrupted at the reductive elimination step has been applied to the synthesis of oxa- and azapalladacycles with the general formula cis-[PdArR(L)2]. The synthesis of oxapalladacycles was achieved under mild conditions by reaction of 2-iodo- or 2-bromophenyloxymethylstannanes with [Pd(PPh3)4]. The synthesis of an aza analogue was similarly carried out from the corresponding 2-iodoaniline derivative. One of the substituted oxapalladacycles rearranged to release steric strain between the palladium and a chloride substituent on the aryl ring, an isomerization promoted by traces of water. In one case, the arylpalladium(II) intermediate of oxidative addition was isolated by using a palladium(0) complex with a bidentate diphosphane. A variety of new palladacycles, including complexes with weakly coordinating ligands, were prepared by ligand substitution. Reaction of the palladacycles with dimethyl acetylene-dicarboxylate led to the formation of chromenes or dihydroquinolines by insertion followed by reductive elimination.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/chem.19960021219
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