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Nickel‐ and Palladium‐Catalyzed Cross‐Coupling Reactions at the Bridgehead of Bicyclo[1.1.1]pentane Derivatives ‐ A Convenient Access to Liquid Crystalline Compounds Containing Bicyclo[1.1.1]pentane Moieties
Author(s) -
Messner Matthias,
Kozhushkov Sergei I.,
de Meijere Armin
Publication year - 2000
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 - 10.1002/1099-0690(200004)2000:7<1137::aid-ejoc1137>3.0.co;2-2
Subject(s) - chemistry , bicyclic molecule , transmetalation , pentane , palladium , medicinal chemistry , propellane , catalysis , aryl , reagent , organic chemistry , alkyl
Radical addition reactions of organyl iodides 7a ‐ s onto [1.1.1]propellane ( 2 ) followed by halogen‐lithium exchange and transmetallation with zinc chloride, as well as additions of Grignard reagents to 2 , have furnished a variety of 3‐substituted bicyclo[1.1.1]pentyl‐1‐magnesium ( 14 ) and ‐zinc ( 19 ) derivatives. The latter have been coupled with various alkenyl, aryl, and biaryl halides and triflates under NiCl 2 dppe, Pd(PPh 3 ) 4 , or PdCl 2 (dppf) catalysis to give a number of 1,3‐disubstituted bicyclo[1.1.1]pentyl derivatives 17 , 20 , and 23 , several of which exhibit liquid crystalline properties, in moderate to very good yields. The coupling products 20ca , 23ab , 23ae , 23ff , and 23fg have been further transformed to yield bicyclo[1.1.1]pentyl derivatives 32 , 24ab , 24ae , 27ff , and 27fg , respectively, bearing alkynyl, cyano, and/or alkenyl groups.