Co-reporter:Vasily N. Tsarev, Yuna Morioka, Joaquim Caner, Qing Wang, Richiro Ushimaru, Akihiko Kudo, Hiroshi Naka, and Susumu Saito
Organic Letters 2015 Volume 17(Issue 10) pp:2530-2533
Publication Date(Web):April 27, 2015
DOI:10.1021/acs.orglett.5b01063
N-Methylation of amines with methanol proceeds at room temperature in the presence of a silver-loaded titanium dioxide (Ag/TiO2) photocatalyst under UV–vis light irradiation. This method allows facile synthesis/isolation of N-methylamines bearing various functional groups including N-benzyl, N-allyl, N-Boc, hydroxyl, ether, acetal, carboxamide, formamide, and olefin groups.
Co-reporter:Joaquim Caner, Zijun Liu, Yuki Takada, Akihiko Kudo, Hiroshi Naka and Susumu Saito
Catalysis Science & Technology 2014 vol. 4(Issue 11) pp:4093-4098
Publication Date(Web):30 Jun 2014
DOI:10.1039/C4CY00329B
Photochemical transformation of biomass-derived or renewable substances with promising scalability is an important challenge for promoting green and sustainable chemistry. We report here that photocatalytic transfer hydrogenolysis of allyl alcohol (obtained from glycerol) gives potentially sustainable propylene with high chemo- and redox selectivity, promoted by powdered Pd/TiO2 in CH3OH (obtained from CO2) under near-ultraviolet–visible light irradiation (λ > 365 nm) at ambient temperature.
Co-reporter:Yuki Takada, Siong Wan Foo, Yusuke Yamazaki and Susumu Saito
RSC Advances 2014 vol. 4(Issue 92) pp:50851-50857
Publication Date(Web):01 Oct 2014
DOI:10.1039/C4RA09609F
Herein, catalytic fluoride (F−) is demonstrated to be a trigger for dehydrative immobilization of atmospheric pressure CO2, such that reaction of CO2 with β-amino alcohols derived from natural amino acids gives optically pure oxazolidinones in high yields. A synergistic combination of fluoride and organosilicon agents (e.g., Bu4NF + Ph3SiF or siloxanes) enhances the catalytic activity and functional group compatibility. This system lies at the interface between homogenous and heterogeneous catalysis, and may prove useful for the development of recoverable/reusable siloxane-based CO2 immobilization materials.
Co-reporter:Kazuki Iida, Takashi Miura, Junki Ando, and Susumu Saito
Organic Letters 2013 Volume 15(Issue 7) pp:1436-1439
Publication Date(Web):March 7, 2013
DOI:10.1021/ol4001262
A virtually salt-free and straightforward bimolecular assembly giving N-unsubstituted pyrroles through fully unmasked α-amino aldehydes, which was enabled by the dual effects of a catalytic ruthenium complex and an alkali metal base, is reported. Either solvent-free or acceptorless dehydrogenation facilitates high atom, step, and pot economy, which are otherwise difficult to achieve in multistep operations involving protection/deprotection.
Co-reporter:Siong Wan Foo, Yuki Takada, Yusuke Yamazaki, Susumu Saito
Tetrahedron Letters 2013 Volume 54(Issue 35) pp:4717-4720
Publication Date(Web):28 August 2013
DOI:10.1016/j.tetlet.2013.06.100
Dehydrative synthesis of oxazolidinones from amino alcohols and CO2 was achieved in the presence of alkali metal carbonates such as Cs2CO3 as catalyst. It is noteworthy that 1 atm of CO2 is enough for the reaction to proceed and no special dehydrating agent is required in this system. A mechanstic study showed that the OH of amino alcohol acts as nucleophile and the OH in the carbamic acid moiety is liberated during the cyclization process.
Co-reporter:Takashi Miura, Ingmar E. Held, Shunsuke Oishi, Masayuki Naruto, Susumu Saito
Tetrahedron Letters 2013 Volume 54(Issue 21) pp:2674-2678
Publication Date(Web):22 May 2013
DOI:10.1016/j.tetlet.2013.03.047
A general method for catalytic hydrogenation of unactivated amides was achieved. During the catalyst induction period, a novel structural change was observed involving full hydrogenation of the interior unsaturated bonds of the pyridines of the Ru-containing catalyst precursor. Based on this observation, the mechanism of amide hydrogenation may involve a two-step pathway, wherein the Ru catalyst having an H–Ru–N–H functionality is generated in the first step, followed by the amide carbonyl group interacting with the outer, rather than the inner, sphere of the Ru catalyst.
Co-reporter:Dr. Zijun Liu;Dr. Joaquim Caner;Dr. Akihiko Kudo;Dr. Hiroshi Naka;Dr. Susumu Saito
Chemistry - A European Journal 2013 Volume 19( Issue 29) pp:9452-9456
Publication Date(Web):
DOI:10.1002/chem.201301347
Co-reporter:Siong Wan Foo, Shun Oishi, Susumu Saito
Tetrahedron Letters 2012 Volume 53(Issue 40) pp:5445-5448
Publication Date(Web):3 October 2012
DOI:10.1016/j.tetlet.2012.07.129
We have developed a new method for the direct aldol condensation of unactivated amides using 1,3,5-triazo-2,4,6-triphosphorine-2,2,4,4,6,6-hexachloride (TAPC)-based phosphorous/SO42− catalysis. The SO42− species in a reaction mixture enhances the reaction rate of the catalysis. In principle, no metal sources are required for the generation of the catalyst, and there is no requirement for the use of stoichiometric quantities of an acid or base. This catalyst system is operative under relatively acidic conditions. One major advantage of carrying out the reaction under acidic conditions is that both aldehydes and acetals are capable of undergoing carbon–carbon bond formation at the α-carbon of amide carbonyl groups through dehydration.
Co-reporter:Shunsuke Oishi;Dr. Susumu Saito
Angewandte Chemie International Edition 2012 Volume 51( Issue 22) pp:5395-5399
Publication Date(Web):
DOI:10.1002/anie.201200304
Co-reporter:Shunsuke Oishi;Dr. Susumu Saito
Angewandte Chemie 2012 Volume 124( Issue 22) pp:5491-5495
Publication Date(Web):
DOI:10.1002/ange.201200304
Co-reporter:Dr. Yingsheng Zhao;Siong Wan Foo;Dr. Susumu Saito
Angewandte Chemie 2011 Volume 123( Issue 13) pp:3062-3065
Publication Date(Web):
DOI:10.1002/ange.201006660
Co-reporter:Dr. Ya Du;Shunsuke Oishi;Dr. Susumu Saito
Chemistry - A European Journal 2011 Volume 17( Issue 44) pp:12262-12267
Publication Date(Web):
DOI:10.1002/chem.201102446
Co-reporter:Dr. Yingsheng Zhao;Siong Wan Foo;Dr. Susumu Saito
Angewandte Chemie International Edition 2011 Volume 50( Issue 13) pp:3006-3009
Publication Date(Web):
DOI:10.1002/anie.201006660
Co-reporter:Dr. Akihiro Goto;Dr. Hiroshi Naka;Dr. Ryoji Noyori;Dr. Susumu Saito
Chemistry – An Asian Journal 2011 Volume 6( Issue 7) pp:1740-1743
Publication Date(Web):
DOI:10.1002/asia.201000921
Co-reporter:Takashi Miura;Osamu Kose;Dr. Feng Li;Dr. Sun Kai;Dr. Susumu Saito
Chemistry - A European Journal 2011 Volume 17( Issue 40) pp:11146-11151
Publication Date(Web):
DOI:10.1002/chem.201101752
Co-reporter:Osamu Kose and Susumu Saito
Organic & Biomolecular Chemistry 2010 vol. 8(Issue 4) pp:896-900
Publication Date(Web):17 Dec 2009
DOI:10.1039/B914618K
A cross-coupling reaction of different alcohols was achieved using a pincer-type NHC/PdBr complex as the catalyst precursor, and the reaction, under either Ar or H2 gas, displayed a broad substrate scope with respect to both primary and secondary alcohol components, with high alcohol product selectivity.
Co-reporter:Yusuke Yamazaki, Kasumi Kakuma, Ya Du, Susumu Saito
Tetrahedron 2010 66(51) pp: 9675-9680
Publication Date(Web):
DOI:10.1016/j.tet.2010.10.051
Co-reporter:Shunsuke Oishi ; Junichi Yoshimoto
Journal of the American Chemical Society 2009 Volume 131(Issue 25) pp:8748-8749
Publication Date(Web):June 4, 2009
DOI:10.1021/ja9029494
We disclosed structural dynamics hidden behind a series of aminoorganoboron (AOB) compounds that involved a recombinant of covalent, dative, and hydrogen bonds. A combination process occurred via reorganizing elements and bonds between the two major structures (open and closed), which were chemically switchable through precise adjustment of either acidic or basic conditions. The structural dynamics favoring an open structure seem to be more important for catalysis, as represented by methanolysis of activated amides.
Co-reporter:Joaquim Caner, Zijun Liu, Yuki Takada, Akihiko Kudo, Hiroshi Naka and Susumu Saito
Catalysis Science & Technology (2011-Present) 2014 - vol. 4(Issue 11) pp:NaN4098-4098
Publication Date(Web):2014/06/30
DOI:10.1039/C4CY00329B
Photochemical transformation of biomass-derived or renewable substances with promising scalability is an important challenge for promoting green and sustainable chemistry. We report here that photocatalytic transfer hydrogenolysis of allyl alcohol (obtained from glycerol) gives potentially sustainable propylene with high chemo- and redox selectivity, promoted by powdered Pd/TiO2 in CH3OH (obtained from CO2) under near-ultraviolet–visible light irradiation (λ > 365 nm) at ambient temperature.
Co-reporter:Osamu Kose and Susumu Saito
Organic & Biomolecular Chemistry 2010 - vol. 8(Issue 4) pp:NaN900-900
Publication Date(Web):2009/12/17
DOI:10.1039/B914618K
A cross-coupling reaction of different alcohols was achieved using a pincer-type NHC/PdBr complex as the catalyst precursor, and the reaction, under either Ar or H2 gas, displayed a broad substrate scope with respect to both primary and secondary alcohol components, with high alcohol product selectivity.