Tatsuya Uchida 교수

Nitrogen functional groups are found in many biologically active compounds and their stereochemistry has a profound effect on biological activity. Nitrene transfer reactions such as aziridination, C-H bond amination, and sulfimidation are useful methods for introducing nitrogen functional groups, and the enantiocontrol of the reactions has been extensively investigated. Although high enantioselectivity has been achieved, most of the reactions use (N-arylsulfonylimino)phenyliodinane, which co-pro

C–H bonds are ubiquitous and abundant in organic molecules. If C–H bonds could be directly converted to desired functional groups in a chemo‐, site‐, and stereoselective manner, C–H functionalization would be a strong and useful tool for organic synthesis. Recent developments in catalytic and enzymatic chemistry have achieved highly sustainable and selective nitrene C–H insertion. Initially, C–H amination was inspired by model studies on enzymatic oxidation and used iminoiodinanes, nitrogen anal

(ON+)(salen)ruthenium(II) complex - photo-activation - cyclopropanation - cis-selectivity

The asymmetric nitrene transfer reaction is a useful and strong tool for the construction of nitrogen functional groups such as <i>N-</i>sulfonyl amide and carbamic ester in a highly enantioselective manner. On the other hand, there is a substantial limitation in this filed: the transfer of <i>N</i>-acyl amide via the corresponding nitrene intermediates is still difficult because <i>N</i>-acyl nitrenes undergo undesired nitrene dimerization or Curtius rearrangement. Herein, we achieved highly en

(Aqua)ruthenium(salen) complex <b>1c</b> achieved good to high chemo- and enantioselective oxidative cross-coupling of arenols. The catalytic system can be used to selectively produce <i>C</i>₁-symmetric bis(arenol)s from the combination of C3- and C7-substituted 2-naphthols or phenols even when there is no significant difference in oxidation potential between the cross-coupling partners. This unique cross-selectivity is dominated by steric rather than electronic effects of the arenol

The reaction of styrene and t-butyl α-diazoacetate in the presence of (R,R)-(ON+)(salen)ruthenium(II) complex 1 under the irradiation of incandescent light in THF gave the corresponding (1S,2R)-cyclopropanecarboxylate with high stereoselectivity of 99% ee (cis : trans = 96 : 4), while the same reaction in hexane gave the enantiomeric (1R,2S)-cyclopropanecarboxylate preferentially (83% ee, cis : trans = 68 : 32).

A series of chiral (salen)cobalt(III) complexes (salen=[bis(salicylidene)ethylenediaminato]={{2,2′-[(ethane-1,2-diyl)bis[(nitrilo-κN)methylidyne]bis[phenolato-κO]}(2−)}) of cis-β structure were prepared and used for the enantioselective Baeyer-Villiger oxidation of prochiral cyclobutanones with hydrogen peroxide as terminal oxidant. Both cationic (salen)cobalt(III) and neutral iodo(salen)cobalt(III) complexes 3–5 and 7–12, respectively, all having a chiral binaphthalenediamine unit, were found t

Abstract C–H bonds are ubiquitous and abundant in organic molecules. If such C–H bonds can be converted into the desired functional groups in a site-, chemo-, diastereo-, and enantio-selective manner, the functionalization of C–H bonds would be an efficient tool for step-, atom- and redox-economic organic synthesis. C–H oxidation, as a typical C–H functionalization, affords hydroxy and carbonyl groups, which are key functional groups in organic synthesis and biological chemistry, directly. Recen