Yasushi Nishihara  Mikihiro Miyazaki  Yasumasa Tomita  Yuuki Kadono  Kentaro Takagi 《Journal of polymer science. Part A, Polymer chemistry》2008,46(23):7913-7918

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Yasumasa Takenaka  Takanori Shima  Jens Baldamus  Zhaomin Hou 《Angewandte Chemie (International ed. in English)》2009,48(42):7888-7891

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Pan L  Zhang K  Nishiura M  Hou Z 《Angewandte Chemie (International ed. in English)》2011,50(50):12012-12015

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Yasumasa Kanekiyo  Ryuichi Naganawa  Hiroaki Tao 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2003,115(26):3122-3124

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  总被引：1，自引：0，他引：1  

Ishii Y  Takenaka Y  Konishi K 《Angewandte Chemie (International ed. in English)》2004,43(20):2702-2705

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Nemoto T  Hamada Y 《Chemical record (New York, N.Y.)》2007,7(3):150-158

This paper describes the development of a new class of chiral phosphorus ligand: aspartic acid-derived P-chirogenic diaminophosphine oxides, DIAPHOXs, and their application to several Pd-catalyzed asymmetric allylic substitution reactions. Pd-catalyzed asymmetric allylic alkylation was initially examined in detail using diaminophosphine oxides 1a, resulting in the highly enantioselective construction of quaternary stereocenters. Mechanistic investigations revealed that 1a is activated by N,O-bis(trimethylsilyl)acetamide-induced tautomerization to afford a trivalent diamidophosphite species 12, which functions as the actual ligand. Furthermore, asymmetric allylic amination was examined using Pd-DIAPHOX catalyst systems, providing a variety of chiral allylic amines.  相似文献   

    

Dr. Tetsuhiro Nemoto  Zengduo Zhao  Takuya Yokosaka  Yuta Suzuki  Riliga Wu  Prof. Dr. Yasumasa Hamada 《Angewandte Chemie (International ed. in English)》2013,52(8):2217-2220

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Yttrium‐Catalyzed Addition of Benzylic C?H Bonds of Alkyl Pyridines to Olefins     

Dr. Bing‐Tao Guan  Dr. Baoli Wang  Dr. Masayoshi Nishiura  Prof. Dr. Zhaomin Hou 《Angewandte Chemie (International ed. in English)》2013,52(16):4418-4421

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Ohishi T  Zhang L  Nishiura M  Hou Z 《Angewandte Chemie (International ed. in English)》2011,50(35):8114-8117

Caught in the act: N-Heterocyclic carbene copper(I) complexes (1; IPr=1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene) serve as an excellent catalyst for the carboxylation of alkylboranes (2; R=alkyl) with CO(2) to afford a variety of functionalized carboxylic acids (3) in high yields. A novel copper methoxide/alkylborane adduct (A) and its subsequent CO(2) insertion product (B) have been isolated and shown to be true active catalyst species.  相似文献   

    

Min JZ  Suzuki Y  Tomiyasu Y  Jin D  Higashi T  Lee YI  Toyo'oka T 《Rapid communications in mass spectrometry : RCM》2011,25(19):2911-2922

With Boc-Asn-GlcNAc as a basic structure, four permanently positively charged kinds of new acceptors (GP-Boc-Asn-GlcNAc, GT-Boc-Asn-GlcNAc, HMP-Boc-Asn-GlcNAc, MPDPZ-Boc-Asn-GlcNAc) and five kinds of similar structure acceptors (2-PA-Boc-Asn-GlcNAc, 3-PA-Boc-Asn-GlcNAc, 4-PA-Boc-Asn-GlcNAc, HP-Boc-Asn-GlcNAc, PDPZ-Boc-Asn-GlcNAc) were synthesized as acceptors for the resolution of oligosaccharides in glycopeptides. The synthesized acceptors enzymatically reacted with Disialo-Asn (donor) in the presence of Endo-M. The reaction yields of each transglycosylation product were not obvious, because we do not have all the authentic Disialo-Asn-Boc-acceptors. Therefore, we used the peak area of the transglycosylation product detected by mass spectrometry and evaluated the utility of each acceptor. Among the Boc-Asn-GlcNAc acceptors, the positively charged MPDPZ derivative peak area was the highest, MPDPZ-Boc-Asn-GlcNAc with a positively charged structure showed about a 2.2 times greater sensitivity of the transglycosylation product compared to the conventional fluorescence acceptor DBD-PZ-Boc-Asn-GlcNAc. As a result, the MPDPZ-Boc-Asn-GlcNAc acceptor was suitable for the transglycosylation reaction with Endo-M. The development of a qualitative determination method for the N-linked oligosaccharides in glycoproteins was attempted by combination of the transglycosylation reaction and semi-micro high-performance liquid chromatography/electrospray ionization quadrupole time-of-flight tandem mass spectrometry (HPLC/ESI-QTOF-MS/MS). The asparaginyl-oligosaccharides in glycoproteins, liberated by treatment with Pronase E, were separated, purified and labeled with positively charged MPDPZ. The resulting derivatives were separated by a semi-micro HPLC system. The eluted N-linked oligosaccharide derivatives were then introduced into a QTOF-MS instrument and sensitively detected in the ESI(+) mode. Various fragment ions based on the carbohydrate units appeared in the MS/MS spectra. Among the peaks, m/z 782.37 corresponding to MPDPZ-Boc-Asn-GlcNAc is the most important one for identifying the asparaginyl-oligosaccharides. Disialo-Asn-Boc-MPDPZ was easily identified by the selected-ion chromatogram at m/z 782.37 by MS/MS detection. Therefore, the identification of N-linked oligosaccharides in glycoproteins seems to be possible by the proposed semi-micro HPLC separations followed by the QTOF-MS/MS detection. Furthermore, several oligosaccharides in ovalbumin and ribonuclease B were successfully identified by the proposed procedure.  相似文献