Effect of Electronic Structures of Au Clusters Stabilized by Poly(N-vinyl-2-pyrrolidone) on Aerobic Oxidation Catalysis

2009 ◽  
Vol 131 (20) ◽  
pp. 7086-7093 ◽  
Author(s):  
Hironori Tsunoyama ◽  
Nobuyuki Ichikuni ◽  
Hidehiro Sakurai ◽  
Tatsuya Tsukuda
2018 ◽  
Author(s):  
Asim Maity ◽  
Sung-Min Hyun ◽  
Alan Wortman ◽  
David Powers

<p>Hypervalent iodine(V) reagents, such as Dess-Martin periodinane (DMP) and 2-iodoxybenzoic acid (IBX), are broadly useful oxidants in chemical synthesis. Development of strategies to access these reagents from O2 would immediately enable use of O2 as a terminal oxidant in a broad array of substrate oxidation reactions. Recently we disclosed the aerobic synthesis of I(III) reagents by intercepting reactive oxidants generated during aldehyde autoxidation. Here, we couple aerobic oxidation of iodobenzenes with disproportionation of the initially generated I(III) compounds to generate I(V) reagents. The aerobically generated I(V) reagents exhibit substrate oxidation chemistry analogous to that of DMP. Further, the developed aerobic generation of I(V) has enabled the first application of I(V) intermediates in aerobic oxidation catalysis.</p>


2007 ◽  
Vol 111 (13) ◽  
pp. 4885-4888 ◽  
Author(s):  
Nirmalya K. Chaki ◽  
Hironori Tsunoyama ◽  
Yuichi Negishi ◽  
Hidehiro Sakurai ◽  
Tatsuya Tsukuda

ACS Catalysis ◽  
2010 ◽  
Vol 1 (1) ◽  
pp. 2-6 ◽  
Author(s):  
Yongmei Liu ◽  
Hironori Tsunoyama ◽  
Tomoki Akita ◽  
Songhai Xie ◽  
Tatsuya Tsukuda

2020 ◽  
Author(s):  
Ruipu Zhang ◽  
Long Zhang ◽  
Ming-Tian Zhang ◽  
Sanzhong Luo

<p>Oxidation reactions are fundamental transformations in organic synthesis and chemical industry. With oxygen or air as terminal oxidant, aerobic oxidation catalysis provides the most sustainable and economic oxidation processes. Most aerobic oxidation catalysis employs redox metal as its active center. While nature provides non-redox metal strategy as in pyrroloquinoline quinone (PQQ)-dependent methanol dehydrogenases (MDH), such an effective chemical version is unknown. Inspired by the recently discovered rare earth metal-dependent enzyme Ln-MDH, here we show that an open-shell semi-quinone anionic radical species in complexing with lanthanum could serve as a very efficient aerobic oxidation catalyst under ambient conditions. In this catalyst, the lanthanum metal serves only as a Lewis acid promoter and the redox process occurs exclusively on the semiquinone ligand. The catalysis is initiated by 1e<sup>-</sup>-reduction of lanthanum-activated <i>ortho</i>-quinone to a semiquinone-lanthanum complex La(<b>SQ<sup>-.</sup></b>)<sub>2</sub>, which undergoes a coupled O-H/C-H dehydrogenation for aerobic oxidation of alcohols with up to 330 h<sup>-1</sup> TOF. This study suggests a possible functional mode of semiquinone radicals, widely observed with quinoproteins in Nature. Moreover, this unique reductive activation strategy as well as the resulted radical anion as redox ligand creates a new turning point in the development of efficient aerobic oxidation catalysis.</p>


2021 ◽  
Author(s):  
Jaeyune Ryu ◽  
Daniel Bregante ◽  
William C. Howland ◽  
Ryan P. Bisbey ◽  
Corey J. Kaminsky ◽  
...  

<div> <p><b>Heterogeneous aqueous-phase aerobic oxidations are an important emerging class of catalytic transformations, particularly for upgrading next generation bio-derived substrates. The mechanism of these reactions and the precise role of O<sub>2</sub> in particular remains unclear. Herein, we test the hypothesis that thermochemical aerobic oxidation proceeds via two coupled electrochemical half-reactions for oxygen reduction and substrate oxidation. We collect</b><b> electrochemical and thermochemical data on common noble metal catalysts under identical reaction/transport environments, and find that the electrochemical polarization curves of the O<sub>2</sub> reduction and the substrate oxidation half-reaction closely predict the mixed potential of the catalyst measured <i>in operando</i> during thermochemical catalysis across 13 diverse variables spanning </b><b>reaction conditions, catalyst composition, reactant identity, and pH</b><b>. Additionally, we find that driving the oxidation half-reaction reaction electrochemically in the absence of O<sub>2</sub> at the mixed potential leads to very similar rates and selectivities as for the thermochemical reaction in all cases examined. These findings strongly indicate that the role of O<sub>2</sub> in thermochemical aerobic oxidation is solely as an electron scavenger that provides an incipient electrochemical driving force for substrate oxidation. These studies provide a </b><b>quantitative and predictive link between thermochemical and electrochemical catalysis, thereby enabling the rational design of new thermochemical liquid-phase aerobic oxidation schemes by applying the principles of electrochemistry.</b></p> </div> <br>


Synlett ◽  
2018 ◽  
Vol 30 (03) ◽  
pp. 257-262 ◽  
Author(s):  
Asim Maity ◽  
David Powers

Here, we highlight the recent development of aerobic oxidation catalysis via hypervalent I(III) and I(V) intermediates. The described chemistry intercepts reactive intermediates generated during aldehyde autoxidation to accomplish the oxidation of aryl iodides. The aerobically generated hypervalent iodine intermediates are utilized to couple an array of substrate functionalization chemistry to the reduction of O2.1 Introduction2 Chemistry of Aerobically Generated I(III) Intermediates3 Chemistry of Aerobically Generated I(V) Intermediates4 Conclusions


2012 ◽  
Vol 22 (20) ◽  
pp. 10200 ◽  
Author(s):  
Shyam Biswas ◽  
Michael Maes ◽  
Amarajothi Dhakshinamoorthy ◽  
Mark Feyand ◽  
Dirk E. De Vos ◽  
...  

ChemInform ◽  
2014 ◽  
Vol 45 (26) ◽  
pp. no-no
Author(s):  
Qun Cao ◽  
Laura M. Dornan ◽  
Luke Rogan ◽  
N. Louise Hughes ◽  
Mark J. Muldoon

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