Ylide Ligands
نویسنده
چکیده
The use of ylides of P, N, As or S as ligands toward transition metals is still a very active research area in organometallic chemistry. This fact is mainly due to the nucleophilic character of the ylides and to their particular bonding properties and coordination modes. They can behave as monodentate or bidentate –chelate or bridging– species, they can be used as chiral auxiliary reagents, they are interesting reaction intermediates or useful starting materials in a wide variety of processes, etc. The most interesting bonding properties, structural features and applications of these versatile compounds will be covered in this chapter.
منابع مشابه
Stereoselective synthesis of three-membered ring compounds via ylide routes
Three types of small ring compounds (epoxides, aziridines and cyclopropanes) can be synthesized stereoselectively via ylide route. Among them, the stereochemistry of vinyloxiranes, vinylaziridines, cyclopropylesters, amides and ketones can be tuned by the choice of reaction conditions and ylides with varying heteroatoms and ligands. Optically active epoxides and acetylenylaziridines can be prep...
متن کاملUsing Ylide Functionalization to Stabilize Boron Cations
The metalated ylide YNa [Y=(Ph3 PCSO2 Tol)- ] was employed as X,L-donor ligand for the preparation of a series of boron cations. Treatment of the bis-ylide functionalized borane Y2 BH with different trityl salts or B(C6 F5 )3 for hydride abstraction readily results in the formation of the bis-ylide functionalized boron cation [Y-B-Y]+ (2). The high donor capacity of the ylide ligands allowed th...
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A highly stereoselective [2,3]-sigmatropic rearrangement of sulfur ylide generated through Cu(I) carbene and allyl and propargyl sulfides by a double asymmetric induction approach that combines a chiral camphor sultam auxiliary and Cu(I) catalyst with chiral or achiral diimine ligands has been developed.
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Disparate properties of gold(I) converge to produce the first known cube assembly of eight Au(I) atoms connected by four N-bridging amidinate ligands on the sides of the cube, capped above and below by hyper-coordinate carbon atoms from a phosphorous ylide. There are no phosphines coordinated to the Au(I) atoms. The cluster is formulated as [Au8{CH(NC8H9)2}4{(ηC)P(C6H5)2(CH3)}2]. It displays a ...
متن کاملEnantioselective Intramolecular CH - Insertions upon Cu - Catalyzed Decomposition of Phenyliodonium Ylides . †
The Cu-catalyzed intramolecular CH insertion of phenyliodonium ylide 5b has been investigated at 0° C in the presence of several chiral ligands. Enantioselectivities vary in the range of 38–72 %, and are higher than those resulting from reaction of the diazo compound 5c at 65° C. The results are consistent with a carbenoid mechanism for Cu-catalyzed decomposition of phenyliodonium ylides.
متن کاملBifunctional AgOAc-catalyzed asymmetric [3 + 2] cycloaddition of azomethine ylides.
[reaction: see text] A bifunctional AgOAc-catalyzed asymmetric cycloaddition of azomethine ylides with electronic-deficient alkenes was developed using ferrocenyloxazoline-derived N,P ligands. The reactive metal-bound azomethine ylide dipole is formed by the deprotonation with acetate, and extra base is not necessary. The reactions proceed with high enantioselectivity. This method provides an e...
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