Abstract 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, sulfimidation useful methods for introducing nitrogen groups, the enantiocontrol of been extensively investigated. Although high enantioselectivity achieved, most use ( N ‐arylsulfonylimino)phenyliodinane, which co‐produces iodobenzene, nitrene precursor have low atom...

'Salen' along: The iridium(III)–salen complex 1 efficiently catalyzes the title reaction of 2-ethylbenzenesulfonyl azides to give five-membered sultams with high enantioselectivity. Other 2-alkyl-substitued substrates lead five- and six-membered enantioselectivity; regioselectivity depends upon substrate catalyst used. EDG=electron-donating group.

Smooth salen: Ru(CO)–salen complex 1 is an effective catalyst for asymmetric benzylic and allylic CH bond amination using 2-(trimethylsilyl)ethanesulfonyl azide (SESN3) as the nitrene source. The reaction proceeded with high enantioselectivity excellent regioselectivity. An ethyl group can be selectively aminated, even in presence of n-propyl group. No migration or isomerization double was observed.

Ru(NO)−salen complexes were found to catalyze asymmetric aerobic oxygen atom transfer reactions such as sulfide oxidation and epoxidation in the presence of water under visible light irradiation at room temperature. Oxidation sulfides including alkyl aryl 2-substituted 1,3-dithianes using complex 2 catalyst proceeded with moderate high enantioselectivity up 98% ee, conjugated olefins 3 good 76−92% ee. Unlike biological that need a proton electron system, this reaction requires neither system...

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

Two stable and optically active iridium-salen complexes were synthesized by introducing a tolyl or phenyl ligand at the apical position, respectively, via S(E)Ar mechanism, they found to be efficient catalysts for cis-selective asymmetric cyclopropanation. The scope of cyclopropanation was wide, reactions not only conjugated mono-, di-, trisubstituted olefins but also nonconjugated terminal proceeded with high enantio- cis-selectivity, even in presence functional group such as an ether...

S. Nishizawa, H. Kaneda, T. Uchida and N. Teramae, J. Chem. Soc., Perkin Trans. 2, 1998, 2325 DOI: 10.1039/A805075I

A new robust fluorinated (OC)Ru(salen) complex was designed on the basis of an X-ray structure its parent to show improved turnover numbers (up 878) and enantioselectivities 99%) in aziridination reactions using p-toluenesulfonyl (Ts) or p-nitrobenzenesulfonyl (Ns) azide as nitrene precursor; latter is synthetically advantageous since Ns group N-protecting can be removed under mild conditions.

We synthesized new Ru(salen)(CO) complexes of high durability and achieved aziridination with good to excellent enantioselectivity by using azide compounds that contain an easily removable N-sulfonyl group, such as the 2-(trimethylsilyl)ethanesulfonyl a nitrene precursor. Aziridination less-reactive alpha,beta-unsaturated esters (and amides) proceeded enantioselectivities, from which it is inferred electrophilic species active this reaction. The present asymmetric provides useful tool for...

Ringing the changes: Iridium(III)–salen complexes 1 bearing a σ-coordinated aryl ligand (L=CH3C6H4, C6H5) at apical position are found to efficiently catalyze cis- and enantioselective cyclopropanation of mono- disubstituted olefins (see scheme). Supporting information for this article is available on WWW under http://www.wiley-vch.de/contents/jc_2002/2007/z604385_s.pdf or from author. Please note: The publisher not responsible content functionality any supporting supplied by authors. Any...

A complex situation: Asymmetric epoxidation of conjugated olefins was achieved at room temperature using ruthenium 1 as the catalyst and air oxidant to give epoxides in up 95 % ee (see scheme). When product acid sensitive, reaction carried out 0 °C under oxygen.

Highly enantioselective and good to high-yielding aziridination of conjugated non-conjugated terminal olefins cyclic was achieved using a newly designed Ru(CO)(salen) complex as the catalyst in presence SESN(3) under mild conditions.

(Aqua)ruthenium(salen) complex 1c achieved good to high chemo- and enantioselective oxidative cross-coupling of arenols. The catalytic system can be used selectively produce C1-symmetric bis(arenol)s from the combination C3- C7-substituted 2-naphthols or phenols even when there is no significant difference in oxidation potential between partners. This unique cross-selectivity dominated by steric rather than electronic effects arenols controlled chemoselective single-electron carbon-carbon...

The asymmetric nitrene transfer reaction is a useful and strong tool for the construction of nitrogen functional groups such as N-sulfonyl amide carbamic ester in highly enantioselective manner. On other hand, there substantial limitation this filed: N-acyl via corresponding intermediates still difficult because nitrenes undergo undesired dimerization or Curtius rearrangement. Herein, we achieved imidation sulfides catalytic with (OC)ruthenium–salen complex 2b catalyst 3-substituted...

Cyclopropanation of styrene derivatives with alkyl α-diazoacetate in the presence second-generation (salen)cobalt(II) complex 6 proceeded excellent cis- and enantioselectivity. On other hand, cyclopropanation 14 which was designed on basis mechanism asymmetric induction by showed good trans-

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Baeyer-Villiger oxidation of racemic bicyclic cyclobutanones with Zr[bis(salicylidene)ethylenediaminato] (salen) complex 1 as catalyst in the presence a urea-hydrogen peroxide adduct was found to proceed enantiospecifically. The enantiotopos selection governed primarily by Zr(salen) catalyst, although migratory aptitude (methine > methylene methyl) affected varied extent, depending on substrate structures; one enantiomer gave exclusively normal lactone expected from aptitude, and other an...

Aziridination of vinyl ketones using SESN(3) in the presence Ru(CO)-salen complex 1 provides enantiopure aziridinyl that can serve as useful chiral building blocks. A formal asymmetric synthesis (+)-PD 128907 was achieved an eight-step sequence via aziridination.

A chemoselective hydrogenation of isoquinoline carbocycles was achieved by using the catalyst prepared from Ru(methallyl)2(cod) and trans-chelate chiral ligand PhTRAP. The unique chemoselectivity in this could be ascribed to trans-chelation ligand. procedure for preparing strongly affects reproducibility carbocycle hydrogenation. Various 5-, 6-, 7-, 8-substituted isoquinolines were selectively hydrogenated at their afford 5,6,7,8-tetrahydroisoquinolines as major products high yields with...

Abstract C–H bonds are ubiquitous and abundant in organic molecules. If such can be converted into the desired functional groups a site-, chemo-, diastereo-, enantio-selective manner, functionalization of would an efficient tool for step-, atom- redox-economic synthesis. oxidation, as typical functionalization, affords hydroxy carbonyl groups, which key synthesis biological chemistry, directly. Recently, significant developments have been made using non-heme-type transition-metal catalysts....