TY - JOUR
T1 - Synthesis and Reactivity of Organometallic Intermediates Relevant to Cobalt-Catalyzed Hydroformylation
AU - MacNeil, Connor S.
AU - Mendelsohn, Lauren N.
AU - Zhong, Hongyu
AU - Pabst, Tyler P.
AU - Chirik, Paul J.
N1 - Publisher Copyright:
© 2020 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
PY - 2020/6/2
Y1 - 2020/6/2
N2 - Intermediates relevant to cobalt-catalyzed alkene hydroformylation have been isolated and evaluated in fundamental organometallic transformations relevant to aldehyde formation. The 18-electron (R,R)-(iPrDuPhos)Co(CO)2H has been structurally characterized, and it promotes exclusive hydrogenation of styrene in the presence of 50 bar of H2/CO gas (1:1) at 100 °C. Deuterium-labeling studies established reversible 2,1-insertion of styrene into the Co−D bond of (R,R)-(iPrDuPhos)Co(CO)2D. Whereas rapid β-hydrogen elimination from cobalt alkyls occurred under an N2 atmosphere, alkylation of (R,R)-(iPrDuPhos)Co(CO)2Cl in the presence of CO enabled the interception of (R,R)-(iPrDuPhos)Co(CO)2C(O)CH2CH2Ph, which upon hydrogenolysis under 4 atm H2 produced the corresponding aldehyde and cobalt hydride, demonstrating the feasibility of elementary steps in hydroformylation. Both the hydride and chloride derivatives, (X=H−, Cl−), underwent exchange with free 13CO. Under reduced pressure, (R,R)-(iPrDuPhos)Co(CO)2Cl underwent CO dissociation to form (R,R)-(iPrDuPhos)Co(CO)Cl.
AB - Intermediates relevant to cobalt-catalyzed alkene hydroformylation have been isolated and evaluated in fundamental organometallic transformations relevant to aldehyde formation. The 18-electron (R,R)-(iPrDuPhos)Co(CO)2H has been structurally characterized, and it promotes exclusive hydrogenation of styrene in the presence of 50 bar of H2/CO gas (1:1) at 100 °C. Deuterium-labeling studies established reversible 2,1-insertion of styrene into the Co−D bond of (R,R)-(iPrDuPhos)Co(CO)2D. Whereas rapid β-hydrogen elimination from cobalt alkyls occurred under an N2 atmosphere, alkylation of (R,R)-(iPrDuPhos)Co(CO)2Cl in the presence of CO enabled the interception of (R,R)-(iPrDuPhos)Co(CO)2C(O)CH2CH2Ph, which upon hydrogenolysis under 4 atm H2 produced the corresponding aldehyde and cobalt hydride, demonstrating the feasibility of elementary steps in hydroformylation. Both the hydride and chloride derivatives, (X=H−, Cl−), underwent exchange with free 13CO. Under reduced pressure, (R,R)-(iPrDuPhos)Co(CO)2Cl underwent CO dissociation to form (R,R)-(iPrDuPhos)Co(CO)Cl.
KW - P ligands
KW - acyl complex
KW - asymmetric catalysis
KW - cobalt
KW - structure elucidation
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U2 - 10.1002/anie.202001677
DO - 10.1002/anie.202001677
M3 - Article
C2 - 32182395
AN - SCOPUS:85082953561
SN - 1433-7851
VL - 59
SP - 8912
EP - 8916
JO - Angewandte Chemie - International Edition
JF - Angewandte Chemie - International Edition
IS - 23
ER -