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Palladium(0)‐ and Nickel(0)‐Catalyzed [3 + 2] Co‐Cyclization Reactions of Bicyclopropylidene with Alkenes
Author(s) -
Binger Paul,
Wedemann Petra,
Kozhushkov Sergei I.,
de Meijere Armin
Publication year - 1998
Publication title -
european journal of organic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.825
H-Index - 155
eISSN - 1099-0690
pISSN - 1434-193X
DOI - 10.1002/(sici)1099-0690(199801)1998:1<113::aid-ejoc113>3.0.co;2-1
Subject(s) - chemistry , norbornene , norbornadiene , palladium , regioselectivity , methyl acrylate , medicinal chemistry , catalysis , alkene , stereoselectivity , nickel , stereochemistry , organic chemistry , polymerization , monomer , polymer
Bicyclopropylidene ( 1 ) readily undergoes a palladium(0)‐catalyzed [3 + 2] co‐cyclization with electron deficient alkenes (methyl acrylate, methyl trans ‐crotonate, methyl cinnamate and diethyl fumarate) as well as with some strained alkenes (norbornene, norbornadiene) by distal ring cleavage of one of the three‐membered rings of 1 . All these co‐cyclizations are regioselective with respect to 1 as well as regio‐ and stereoselective with respect to the alkenes to give the corresponding 4‐methylenespiro[2.4]heptane‐ trans ‐6‐carboxylates 2a − 5 with the electron deficient alkenes and the cycloadducts 6 and 7 with the strained alkenes in acceptable to good yields (56 to 83%). In contrast to palladium(0) catalysts nickel(0) complexes catalyze both distal ring opening of 1 and oxidative coupling of the two double bonds when 1 is reacted with e.g. diethyl fumarate. The result is a mixture of the methylenecyclopentane derivative 5 with the [2 + 2] cycloadduct 8 and the cotrimer 9 .