Premium
Mesoionic carbenes: Reactions of 1,3‐diphenyltetrazol‐5‐ylidene with electron‐deficient alkenes, and synthesis and catalytic activities of the (tetrazol‐5‐ylidene)rhodium(I) complexes
Author(s) -
Araki Shuki,
Yokoi Keisaku,
Sato Ryosuke,
Hirashita Tsunehisa,
Setsune JunIchiro
Publication year - 2009
Publication title -
journal of heterocyclic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.321
H-Index - 59
eISSN - 1943-5193
pISSN - 0022-152X
DOI - 10.1002/jhet.61
Subject(s) - mesoionic , chemistry , carbene , dimethyl acetylenedicarboxylate , rhodium , medicinal chemistry , electrophile , catalysis , tetracyanoethylene , hydrazine (antidepressant) , acetylenedicarboxylate , organic chemistry , photochemistry , cycloaddition , chromatography
The reactions of 1,3‐diphenyltetrazol‐5‐ylidene, a rare example of mesoionic carbenes, with electron‐deficient unsaturated compounds were studied. The carbene reacted with dimethyl 1,2,4,5‐tetrazine‐3,6‐dicarboxylate to give a 5‐tetrazoliomethylide, together with hydrazine derivatives. The reaction with tetracyanoethylene gave another methylide in low yield. On the contrary, the reactions with weaker electrophiles, such as 3,6‐diphenyl‐1,2,4,5‐tetrazine, fumalonitrile, N ‐phenylmaleimide, and dimethyl acetylenedicarboxylate, did not give any coupling products, but gave phenylated products and/or Michael addition products via the degradation of the 1,3‐diphenyltetrazole ring. Novel mesoionic mono‐ and bis(carbene)‐rhodium(I) complexes were synthesized and the structures were characterized by X‐ray crystallography. Their catalytic activities for the decarbonylative addition reaction of benzoyl chloride to ethynylbenzene were investigated. J. Heterocyclic Chem., (2009).