In addition, PDA can be deposited on any substrate surface and react with organic molecules through Schiff base or Michael addition reactions
or coordinate with metal ions.
In the case of less bulky and especially bisphosphine chelating ligands, different types of 14-electron Pd[L.sub.2] complexes have been postulated as active catalysts, and corresponding products of the oxidative addition reactions
to such complexes have been characterised [37-40].
Boday et al modified these materials by reacting the resins with 1,4 conjugate addition reactions
to produce a variety of pendant groups and bridging segments for adequate toughness.
In this work, a novel hydrophobically associated polyacrylamide and its modified silica nanocomposite prepared by free radical emulsion copolymerization of hydrophilic and hydrophobic monomers, where silica nanoparticles introduced through backbone structure of the polymer through Michael addition reactions
to guarantee regular distribution of silica nanoparticles through polymer matrix.
[NMP][H2PO4] was used as dual solvent-catalyst for synthesis of AY-alkoxyketones by the oxa-Michael addition reactions
Nevertheless, the potential Michael addition reactions
cannot be ruled out because each BTA molecule contains two >NH groups and one >[CH.sub.2] group and the active hydrogen atoms of these functional groups may lake part in the polymerization of BMI with BTA via the Michael addition reaction
In summary, Feist's acid has been introduced as a new class of hydrogen bond donor catalysts for the activation of nitroalkene in conjugate addition reactions
. This study includes the original report of Feist's acid catalysis of Michel addition of indole and pyrrole to a variety of nitroolefins.
It covers [2+2+2] and related cycloaddition reactions; [4+2], [3+2], and related cycloaddition reactions; electrocyclization reactions; coupling and addition reactions
; and other important transformations.
The higher the value of [DELTA][omega] the more favourable the D-A process, therefore, apart from (4+2) addition reactions
of these TO as diene with the typical dienophiles like 1,2-dicyanoethene and 1,2-dicyanoethyne, it could be possible for TO with strong electron withdrawing substituents to serve as dienophile e.g.
Although chiral ethers-crown are more resistant to decomposition and have been used successfully, for example, in asymmetric Michael addition reactions
, their high cost makes impracticable their use in industrial scale .