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Three different organocatalysts, namely, 1-tert-butyl-4,4,4-tris(dimethylamino)-2,2-bis[tris (dimethylamino) phosphoranylidenamino]-2Λ5,4Λ5-catenadi(phosphazene) (t-BuP4), 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD) and 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU), have been used as 1,5-dioxepan-2-one (DXO) ring-opening polymerization (ROP) catalysts at varied reaction conditions. 1H NMR spectra, size exclusion chromatography (SEC) characterizations, and kinetic studies prove that the (co)polymerizations are proceeded in a controlled manner with the three organocatalysts. It is deduced that t-BuP4 and DBU catalysts are in an initiator/chain end activated ROP mechanism and TBD is in a nucleophilic ROP mechanism.

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An iminotris(dimethylamino)phosphorane (HMP1) phosphazene superbase has been anchored onto poly(hexachlorocyclotriphosphazene‐co‐4,4′‐sulfonyldiphenol) (PZS)‐coated Fe3O4 magnetic nanoparticles (MNPs) through efficient phosphorous‐chloride (from PZS surface) and imino (from HMP1) reaction. Subsequently, these novel heterogeneous Fe3O4@PZS@HMP1 catalysts have been successfully utilized in the ring‐opening polymerization of ε‐caprolactone (ε‐CL) and δ‐valerolactone (δ‐VL). Notably, such catalysts can be easily removed from the reaction mixture and reused 3 times without obvious activity loss.