Premium
Heterogeneous Organocatalysis at Work: Functionalization of Hollow Periodic Mesoporous Organosilica Spheres with MacMillan Catalyst
Author(s) -
Shi Jiao Yi,
Wang Chang An,
Li Zhi Jun,
Wang Qiong,
Zhang Yuan,
Wang Wei
Publication year - 2011
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.201100072
Subject(s) - catalysis , surface modification , mesoporous material , phenylene , mesoporous organosilica , chemical engineering , yield (engineering) , materials science , condensation , particle size , heterogeneous catalysis , chemistry , organic chemistry , mesoporous silica , polymer , composite material , physics , engineering , thermodynamics
We report a new method for the synthesis of hollow‐structured phenylene‐bridged periodic mesoporous organosilica (PMO) spheres with a uniform particle size of 100–200 nm using α‐Fe 2 O 3 as a hard template. Based on this method, the hollow‐structured phenylene PMO could be easily functionalized with MacMillan catalyst (H‐ Ph PMO‐Mac) by a co‐condensation process and a “click chemistry” post‐modification. The synthesized H‐ Ph PMO‐Mac catalyst has been found to exhibit high catalytic activity (98 % yield, 81 % enantiomeric excess ( ee ) for endo and 81 % ee for exo ) in asymmetric Diels–Alder reactions with water as solvent. The catalyst could be reused for at least seven runs without a significant loss of catalytic activity. Our results have also indicated that hollow‐structured PMO spheres exhibit higher catalytic efficiency than solid (non‐hollow) PMO spheres, and that catalysts prepared by the co‐condensation process and “click chemistry” post‐modification exhibit higher catalytic efficiency than those prepared by a grafting method.