Polydentate ligand, addition with

The polydentate ligands 2-(diphenylphosphino)-6-[3-(2 -pyridyl)pyrazol-l-yl)pyridine and 2-(diphenylphosphino)-6-(pyrazol-l-yl)pyridine react with [Ag(NCMe)4]C104 to give the dinuclear complexes where the ligands are P,N,N bonded as in (249).1 82 The reaction of two equivalents of AgBF4 with 6,6-bis(diphenylphosphine)-2,2 -bipyridyl (P2-bipy) gives the complex [Ag4(P2-bipy)2](BF4)4. Addition of Br or I leads to complexes [Ag4X2(P2-... 

Another major contribution of polydentate ligands is the creation of a chiral pocket around the catalytic center providing, an appropriate chiral environment. The chiral pocket concept has been introduced by Trost for catalytic enantioselective allylic alkylation with the tetradentate aminophosphine ligand 33 [133]. The nucleophile fits into the chiral environment created by the chiral ligand and the allyl Pd intermediate. As a result, the enantiocontrol of the newly formed chiral center is very effective. In addition, the chiral control is likely to be efficient even at positions remote from the chiral ligand. That auxiliary has been widely... 

The synthesis of cahx[4]arene dimelamines with different functionalities and their self-assembly with barbituric and cyanuric acid to hydrogen-bonded nanostructures have been published <05OBC3727> Unique ionophores of penta-crown ethers have been prepared by the reaction of l,3,5-triacryloylhexahydro-l,3,5-triazine (TAHTA) with diaza 18-crown-6 followed by Michael addition, and their binding capabilities towards alkali metal cations studied <05SL2257>. New silver complexes of polydentate ligands including a derivative of pyrazol-l-yl-l,3,5-triazine have been reported <05EJ14370>. 

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