Heterogenized Gold(I), Gold(III), and Palladium(II) Complexes for C-C Bond Reactions

Abstract

Recycling of heterogenized gold(I), gold(III), and palladium(II) complexes could be achieved for Suzuki and Sonogashira cross-coupling reaction between iodo benzene and arylboronic acids or alkynes. Au(I) and Pd(II) afford selectively nonsymmetrical biaryl compounds, while gold(III) complexes can only catalyze the arylboronic or alkynes homocoupling. Recycling occurs without loss of the catalytic activity after several reaction cycles.

Layered zeolitic materials: an approach to designing versatile functional solids

“…145 Related with this last approach, Au(I) and Pd(II) complexes were heterogenized onto ITQ-2, obtaining effective catalysts for Sonogashira cross-coupling reactions between iodobenzene and arylboronic acids or alkynes. 146 Stabilized enzymes were also covalently supported onto MWW layers which are forming ITQ-2 zeolites, generating novel biocatalysts. 147 The benefits of the open zeolitic structures, derived from MWW layered precursors, can be exploited in other catalytic fields, more related with electro-or photo-catalysis.…”

Layered Materials with Catalytic Applications: Pillared and Delaminated Zeolites from MWW Precursors

“…Normally, the synthesis is performed in alkaline medium, using sodium as a charge compensating cation [36]. The hydrothermal crystallization occurs between 7 and 12 days at [135][136][137][138][139][140][141][142][143][144][145][146][147][148][149][150] • C if the process is carried out in agitation conditions [37]. On the contrary, if static conditions are employed, the MWW(P) crystallization is more complicated, being possible the coexistence of another zeolitic phases such as Ferrierite or Mordenite [38].…”

“…The elevated accessibility introduced by the structure of the exfoliated supports facilitated the preparation of highly efficient immobilized catalysts with TOFs up to 400 h −1 (Scheme 15) [62]. Similar gold (I), gold (III), and palladium (II) complexes were heterogenized onto disordered MWW materials and used as effective catalysts for Sonogashira cross-coupling reactions between iodobenzene and arylboronic acids or alkynes [144]. [61] Scheme 17: Synthesis of gold-carbene complexes (according to [62]).…”

Crossing the Borders Between Homogeneous and Heterogeneous Catalysis: Developing Recoverable and Reusable Catalytic Systems

“…values in asymmetric reactions provides a unique opportunity to assess how different parameters affect to the performance of a catalytic site. Knowledge on this matter is particularly important for supported catalysts [110][111][112]. As we have commented in the precedent section, very frequently the asymmetric induction of a given transition metal complex when supported is diminished with respect to the enantioselectivity of the same complex in homogeneous phase.…”

“…In the case of porous supports, one drawback of this methodology is that, the active site is occupying the void space, reducing the pore volume and limiting the diffusion of the substrates. This problem has been partially overcome by anchoring the complex in a mesoporous molecular sieve or on delaminated zeolites [110][111][112].…”