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Multistep Organic Transformations over Base‐Rhodium/Diamine‐Bifunctionalized Mesostructured Silica Nanoparticles
Author(s) -
Liao Hang,
Chou Yajie,
Wang Yu,
Zhang Han,
Cheng Tanyu,
Liu Guohua
Publication year - 2017
Publication title -
chemcatchem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.497
H-Index - 106
eISSN - 1867-3899
pISSN - 1867-3880
DOI - 10.1002/cctc.201700436
Subject(s) - rhodium , diamine , nanoparticle , base (topology) , chemical engineering , materials science , chemistry , organic chemistry , polymer chemistry , catalysis , nanotechnology , mathematics , engineering , mathematical analysis
The assembly of multiple catalytic functionalities within a single mesoporous silica as a catalyst for multistep enantioselective organic transformations in an environmentally friendly medium is a significant challenge in heterogeneous asymmetric catalysis. Herein, we took advantage of a BF 4 − anion hydrogen bonding strategy to anchor a chiral cationic rhodium/diamine complex within base‐functionalized mesostructured silica nanoparticles conveniently to construct a bifunctional heterogeneous catalyst. The solid‐state 13 C NMR spectrum discloses the well‐defined chiral Rh/diamine active species, and we used XRD, N 2 adsorption–desorption, and electron microscopy to reveal the ordered mesostructure. The combination of bifunctionality in the silica nanoparticles enables two kinds of efficient enantioselective organic transformations with high yields and enantioselectivities, in which the asymmetric transfer hydrogenation of α‐haloketones followed by epoxidation provides various chiral aryloxiranes, and the amination of α‐haloketones with anilines followed by asymmetric transfer hydrogenation produces various β‐amino alcohols. Furthermore, the catalyst can be recovered and recycled for seven times without a loss of catalytic activity, which is an attractive feature for multistep organic transformations in a sustainable benign process.