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Rhodium(I)‐Catalyzed [2+2+2+2] Cycloaddition of Diynes To Form Cyclooctatetraenes
Author(s) -
Nasrallah Daniel J.,
Croatt Mitchell P.
Publication year - 2014
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/ejoc.201402109
Subject(s) - rhodium , chemistry , catalysis , cycloaddition , reactivity (psychology) , benzene , reductive elimination , medicinal chemistry , benzene derivatives , transition state , organic chemistry , photochemistry , chemical synthesis , medicine , biochemistry , alternative medicine , pathology , in vitro
Unique reactivity of a rhodium catalyst in the presence of many different Lewis basic additives was observed and studied. In the absence of additives, it was observed that a selective [2+2+2] reaction to form benzene products occurred; however, in the presence of an additive, optimally DMSO, the first rhodium(I)‐catalyzed [2+2+2+2] reaction of alkynes occurred. A screen of different additives and catalysts was performed. Finally, a brief mechanistic study performed by using a ReactIR determined that DMSO coordinates to the catalyst, which affects the energetics of the reaction pathway. This appears primarily to raise the transition‐state energy for the reductive elimination to form the benzene products.