Solvent-Induced Assembly of Sliver Coordination Polymers (CPs) as Cooperative Catalysts for Synthesizing of Cyclopentenone[b]pyrroles Frameworks

A series of solvent-induced
Ag-based coordination polymers (CPs) (1–3), which were synthesized by regulating the size, shape,
and polarity of solvent molecules (EtOH, iPrOH, 1,4-dioxane)
as structure-directing agents, has been used as heterogeneous catalysts
to explore how the metal–metal bonds could serve as cooperative
catalysis for tandem acylation–Nazarov cyclization reaction
to prepare cyclopentenone­[b]­pyrroles frameworks. Structural conversions
from a three-dimensional (3D) framework of 1 to the structure
of 2 with Ag–Ag–Ag bonds and to the two-dimensional
(2D) framework of 3 with Ag–Ag bonds, arising
from the different sizes, shapes, and polarities of the solvent molecules,
were observed. Futhermore, the effective cooperative catalysis for
tandem acylation–Nazarov cyclization reaction has been evidenced
by the significantly transformed connection modes of Ag–Ag
interactions in 1–3. As a result,
the unique structural characteristics of 2, especially
containing the Ag–Ag–Ag bonds, endow 2 with
intact multinuclear reaction pathways and well-defined multinuclear
platforms that can execute tandem acylation–Nazarov cyclization
reaction through the cooperative effect of Ag–Ag–Ag
interactions during the catalytic process.