Design of novel chiral N,N,O-tridentate phenanthroline ligands and their application to enantioselective addition of organozinc reagents to aldehydes.
نویسندگان
چکیده
The novel N,N,O-tridentate phenanthroline ligand (BinThro) bearing an axially chiral binaphthyl backbone prepared from BINOL was found to be an effective chiral catalyst for enantioselective addition of diethylzinc to aromatic aldehydes with high enantioselectivity (up to 95% ee).
منابع مشابه
Enantioselective addition of organozinc reagents to carbonyl compounds*
Different chiral camphorsulfonamide derivatives containing a hydroxy or a sulfonamido functionality, as well as chiral 1,2-hydroxysulfonamides, have been evaluated as chiral promoters in the classical enantioselective addition of dialkylzinc reagents to aldehydes in the presence of titanium tetraisopropoxide (ee up to 96 %). Surprisingly, ligands with a structure of isoborneol are able to promo...
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Chiral alcohols are ubiquitous in organic structures. One efficient method to generate chiral alcohols is the catalytic asymmetric addition of a carbon nucleophile to a carbonyl compound since this process produces a C-C bond and a chiral center simultaneously. In comparison with the carbon nucleophiles such as an organolithium or a Grignard reagent, an organozinc reagent possesses the advantag...
متن کاملCu(ii)-catalyzed enantioselective oxygen atom transfer from oxaziridine to oxindole derivatives with chiral phenanthroline.
In the presence of a Cu(ii) complex of axially chiral, N,N,O-tridentate phenanthroline ligand (S)-2, asymmetric oxygen atom transfer of oxindole derivatives (3) using Davis' oxaziridine (4) occurred to give the corresponding 3-aryl-3-hydroxy-2-oxindole derivatives (1) with excellent enantioselectivity (up to 96% ee). The X-ray crystallographic analysis of the isolated Cu(ii) complex disclosed i...
متن کاملSynthesis of novel C2-symmetric chiral bis(oxazoline) ligands and their application in the enantioselective addition of diethylzinc to aldehydes
Novel chiral bis(oxazoline) ligands bearing dibenzo[a,c]cycloheptadiene and a dihydroxy group have been synthesized and their application in the catalytic asymmetric addition of diethylzinc to aldehydes investigated. The enantioselectivities for the aromatic aldehydes are generally high and up to 96% ee was obtained. 2003 Elsevier Ltd. All rights reserved.
متن کاملPhosphoramidites: marvellous ligands in catalytic asymmetric conjugate addition.
The development of an efficient catalytic system for enantioselective carbon-carbon bond formation by 1,4-addition of organometallic reagents (organolithium, Grignard, and organozinc reagents) to enones is a major challenge in organic synthesis. This Account presents the breakthrough realized in this field using chiral phosphoramidite ligands for copper-catalyzed dialkylzinc additions. Applicat...
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عنوان ژورنال:
- Chemical communications
دوره 50 87 شماره
صفحات -
تاریخ انتشار 2014