TY - JOUR
T1 - Exploring bis(cyclometalated) ruthenium(II) complexes as active catalyst precursors
T2 - Room-temperature alkene-alkyne coupling for 1,3-diene synthesis
AU - Zhang, Jing
AU - Ugrinov, Angel
AU - Zhang, Yong
AU - Zhao, Pinjing
PY - 2014/8/4
Y1 - 2014/8/4
N2 - Described is the development of a new class of bis(cyclometalated) ruthenium(II) catalyst precursors for C-C coupling reactions between alkene and alkyne substrates. The complex [(cod)Ru(3-methallyl)2] reacts with benzophenone imine or benzophenone in a 1:2 ratio to form bis(cyclometalated) ruthenium(II) complexes (1). The imine-ligated complex 1a promoted room-temperature coupling between acrylic esters and amides with internal alkynes to form 1,3-diene products. A proposed catalytic cycle involves C-C bond formation by oxidative cyclization, β-hydride elimination, and C-H bond reductive elimination. This RuII/RuIV pathway is consistent with the observed catalytic reactivity of 1a for mild tail-to-tail methyl acrylate dimerization and for cyclobutene formation by [2+2] norbornene/alkyne cycloaddition.
AB - Described is the development of a new class of bis(cyclometalated) ruthenium(II) catalyst precursors for C-C coupling reactions between alkene and alkyne substrates. The complex [(cod)Ru(3-methallyl)2] reacts with benzophenone imine or benzophenone in a 1:2 ratio to form bis(cyclometalated) ruthenium(II) complexes (1). The imine-ligated complex 1a promoted room-temperature coupling between acrylic esters and amides with internal alkynes to form 1,3-diene products. A proposed catalytic cycle involves C-C bond formation by oxidative cyclization, β-hydride elimination, and C-H bond reductive elimination. This RuII/RuIV pathway is consistent with the observed catalytic reactivity of 1a for mild tail-to-tail methyl acrylate dimerization and for cyclobutene formation by [2+2] norbornene/alkyne cycloaddition.
KW - C-H activation
KW - homogeneous catalyst
KW - ligand effects
KW - ruthenium
KW - synthetic methods
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U2 - 10.1002/anie.201402098
DO - 10.1002/anie.201402098
M3 - Article
C2 - 24954299
AN - SCOPUS:84905509828
SN - 1433-7851
VL - 53
SP - 8437
EP - 8440
JO - Angewandte Chemie - International Edition
JF - Angewandte Chemie - International Edition
IS - 32
ER -