Premium
Mechanistic Insights into the Rh(I)/Rh 2 (II)‐Catalyzed Divergent Ring‐Opening of Cyclopropenes: A Computational Study
Author(s) -
Kou Luyao,
Dai Ping,
Bao Xiaoguang
Publication year - 2020
Publication title -
chemcatchem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.497
H-Index - 106
eISSN - 1867-3899
pISSN - 1867-3880
DOI - 10.1002/cctc.202001149
Subject(s) - cyclopropene , chemistry , moiety , regioselectivity , intramolecular force , carbene , rhodium , allylic rearrangement , ring (chemistry) , nucleophile , catalysis , medicinal chemistry , furan , stereochemistry , cyclopropanation , oxidative addition , organic chemistry
The mechanisms of transition‐metal‐catalyzed cyclopropenes involved reactions are complicated since diversified active intermediates could be potentially formed. Herein, computational studies were performed to gain mechanistic insights into the Rh(I)‐ and Rh 2 (II)‐catalyzed regioselective ring‐opening of allylic cyclopropenecarboxylate ( 1 ) and further rearrangement to form Δ β,γ butenolides. For the Rh(I)‐catalyzed ring‐opening of cyclopropene moiety of 1 , an unusual oxidative addition of C−C σ bond of the three‐membered ring onto Rh(I) to form the intermediate with a C−Rh σ bond and a π…Rh interaction is proposed. While, for the Rh 2 (II)‐catalyzed reaction, it is more feasible for the cyclopropene moiety of 1 to convert to the Rh 2 (II) vinyl carbene intermediate. Despite the formation of different key intermediates for the Rh(I) and Rh 2 (II)‐catalyzed ring‐opening reactions, the subsequent intramolecular nucleophilic cyclization to form furan derivatives is similar. In addition, the origins of different regioselectivities for the Rh(I) and Rh 2 (II)‐catalyzed reactions are revealed.