Tanaka catalyst structure

H. Sasai, T. Suzuki, N. Itoh, K. Tanaka, T. Date, K. Oka-mura, M Shibasaki, Catalytic Asymmetric Nitroaldol Reaction Using Optically Active Rare Earth BINOL Complex Investigation of the Catalyst Structure, J. Am Chem Soc 1993,115,10372-10373. 

Figure 6. Structure of the Tanaka catalyst and acid-base reaction of the...

Although there still exist some mechanistic questiorrs and some inconsistencies in theoretical resrrlts from different levels of theory, we summarize here our new theoretical and ejqrerimental studies aimed toward understanding the complicated electrorric and geometric structures of the Tanaka catalyst, and we discuss new directiorrs for kinetic and mechanistic... 

Shimizu, K Takamatsu, M Nishi, K Yoshida, H Satsuma, A Tanaka, T Yoshida, S Hattori, T. Alumina-supported gallium oxide catalysts for NO selective reduction Influence of the local structure of surface gallium oxide species on the catalytic activity, J. Phys. Chem., B, 1999, Volume 103, Issue 9, 1542-1549. 

In 2010, Tanaka s group investigated whether a chiral cyclic a-amino acid included in an oligopeptide chain could catalyze the epoxidation of different enones with high enantiomeric excess. They demonstrated that the a-helical secondary structure of the peptide catalyst is directly related to the chosen a,a-disubstituted amino acid [134]. Thus, they found that 5 mol% of a-helical nonamer 92 with urea-H2O2 as oxidant can catalyze the reaction with ee > 95% (Scheme 12.18). 

Kageyama, H. Miki, K. Tanaka, N. Kasai, N. Ishimori, M. Heki, T. Tsuruta, T. Molecular structure of [Zn(0CH2CH20Me)2(EtZn0CH2CH20Me)g]. An enantiomorphic catalyst for the stereoselective polymerization of methyloxirane. Mo romoZ. Chem., Rapid Commun. 1982, 3, 947-951. 

Following the work of Meyer, Llobet, and Tanaka, the group of Sun also developed a dinuclear water oxidation catalyst based on ruthenium (Fig. 11). From a structural point of view, this system has three distinct... 

Ghosh S, Baik M-H. Redox properties of Tanaka s water oxidation catalyst redox noninnocent ligands dominate the electronic structure and reactivity. Inorg Chem. 2011 50 5946-5957. 

Takahashi R, Sato S., Sodesawa T., Yabuki M. SiUca-alumina catalyst with bimodal pore structure prepared by phase separation in sol-gel process. J. Catal. 2001 200 197-202 Tamagawa H., Oyama K., Yamaguchi T., Tanaka H., Tsuiki H., Ueno A. Control ofNi metal particle size in Ni/Si02 catalysts by calcinations and reduction temperatures. J. Chem. Soc., Faraday Trans. 1 1987 83 3189-3197... 

In the early 1970s, i-proline (222) was shown to function as a chiral catalyst for enantioselective aldol addition reactions (Chapter 4) [156]. With the aim of expanding the scope of proline-catalyzed asymmetric aldol additions [157], List reported that proline also catalyzes enantioselective Mannich reactions (Equation 19) [158]. Whereas most catalytic enantioselective Mannich reactions with aldehydes typically afford the corresponding syn products, Barbas, Tanaka, and Houk demonstrated that the complementary anti products such as 232 could be obtained highly selectively in the presence of the methyl-substituted proline catalyst 229 (99% ee, 98 2 dr. Scheme 11.33) [159]. It was proposed that these transformations proceeded through the energetically favored enamine 230 and transition state structure 231. 

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