Switchable catalysis with a light-responsive cavitand.
Switchable catalysis with a light-responsive cavitand.
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DOI：
10.1002/anie.201105374
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发表时间：
2011-09-26
影响因子：
16.6
通讯作者：
Rebek, Julius, Jr.
中科院分区：
文献类型：
--
作者：
Berryman, Orion B.;Sather, Aaron C.;Lledo, Agusti;Rebek, Julius, Jr.
Host–guest systems that display catalytic behavior represent a promising area of supramolecular chemistry.[1] Supramolecular approaches to cataylst design include ligandtemplated encapsulation,[2] self-assembled ligands, coordination compounds, and artificial biomacromolecules.[3] Generally, these systems operate by binding substrates and stabilizing transition states and/or increasing the effective concentration of reactive species within confined space.[4] In most catalytic host–guest systems the substrate is a guest and substrates that adequately fill the host’s interior are required to ensure activity. Alternatively, there are few instances where the guest is the catalyst.[5] These examples incorporate transition metal guests and enhanced reaction rates are rare.[6] Here we report a complementary approach where the bound guest is an organocatalyst in a deep cavitand. We find that the cavitand/piperidinium complex accelerates the Knoevenagel condensation and show that the rate of the reaction can be controlled using light to stimulate structural changes in the cavitand’s shape.Relatively few examples of photo-switchable catalysis have been described,[7] but our recent experience with photo-controlled guest binding in a cavitand with an azo wall provided an encouraging point of departure.[8] For the present investigation we used short hydrocarbon chains (C2) on the “feet” to facilitate crystallization and incorporated an isopropyl substituent onto the azo wall (Scheme 1). The azo group can be photo-isomerized between
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影响因子：
15
作者：
Brown, Casey J.;Miller, Gregory M.;Raymond, Kenneth N.
通讯作者：
Raymond, Kenneth N.
影响因子：
2.9
作者：
Crecca, Christina R.;Roitberg, Adrian E.
通讯作者：
Roitberg, Adrian E.
影响因子：
15
作者：
Leung, Dennis H.;Bergman, Robert G.;Raymond, Kenneth N.
通讯作者：
Raymond, Kenneth N.
DOI：
10.1039/ct9048500046
发表时间：
1904-01-01
期刊：
JOURNAL OF THE CHEMICAL SOCIETY
影响因子：
--
作者：
Hann, ACO;Lapworth, A
通讯作者：
Lapworth, A
影响因子：
16.6
作者：
Peters, Maike V.;Stoll, Ragnar S.;Hecht, Stefan
通讯作者：
Hecht, Stefan