Phosphine-containing porous organic polymers (phosphine-POPs)
are
a kind of potential catalyst support for alkene hydroformylation.
However, the synthesis of phosphine-POPs with strong π-acceptor
is still a challenge. Herein, we report the synthesis of phosphine-POPs
with different π-acceptor properties [POL-P(Pyr)3, CPOL-BPa&PPh3-15, and CPOL-BP&PPh3-15] and evaluated their performances as ligands to coordinate with
Rh(acac)(CO)2 for hydroformylation of alkenes. We found
that the Rh center with stronger π-acceptor phosphine-POPs showed
better catalytic performance. Rh/CPOL-BPa&PPh3-15 with
strong π-acceptor bidentate phosphoramidites showed obviously
higher activity and regioselectivity (TON = 7.5 × 103, l/b = 26.1) than Rh/CPOL-BP&PPh3-15 (TON = 5.3 ×
103, l/b = 5.0) with weaker π-acceptor bidentate
phosphonites. Particularly, the TON of the hydroformylation reached
27.7 × 103 upon using Rh/POL-P(Pyr)3 which
possessed tris(1-pyrrolyl)phosphane coordination sites. Overall, our
study provides an orientation to design phosphine-POPs for hydroformylation
reactions.