Premium
[2+2] Cycloadditions of Electron‐Poor Acetylenes to (5 Z )‐5‐[(Dimethylamino)methylene]imidazolidine‐2,4‐diones
Author(s) -
Uršič Uroš,
Grošelj Uroš,
Meden Anton,
Svete Jurij,
Stanovnik Branko
Publication year - 2009
Publication title -
helvetica chimica acta
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.74
H-Index - 82
eISSN - 1522-2675
pISSN - 0018-019X
DOI - 10.1002/hlca.200800297
Subject(s) - imidazolidine , chemistry , methylene , medicinal chemistry , acetylene , dimethyl acetylenedicarboxylate , cycloaddition , organic chemistry , catalysis
Microwave‐assisted [2+2] cycloadditions of acetylene mono‐ and acetylenedicarboxylates 2 to (5 Z )‐5‐[(dimethylamino)methylene]imidazolidine‐2,4‐dione 4a or to the corresponding thioxo derivative 4b in MeCN furnished the highly functionalized imidazolidine‐2,4‐dione derivatives 5 and 6 or the corresponding thioxo derivatives 5 – 7 as single isomers or mixtures of two isomers ( Schemes 2 and 3, Table 1 ). When the reaction of (5 Z )‐5‐[(dimethylamino)methylene]imidazolidine‐2,4‐dione ( 4c ) with acetylenedicarboxylate 2a was performed in DMF, hydrolysis of the (dimethylamino)methylene group took place to give (2 E )‐2‐(2,5‐dioxoimidazolidin‐4‐ylidene)butanedioate 11 ( Scheme 5 ).