Cyclopropanation reactions catalysed by dendrimers possessing one metalloporphyrin active site at the core: linear and sigmoidal kinetic behaviour for different dendrimer generations

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• 作者：Petr Vin&scaron ; ^a ; Abel de Có ; zar^b ; ^c ; ^d ; Ivá ; n Rivilla^b ; Kateřina Nová ; ková ; ^e ; Ronen Zangi^b ; ^c ; Josef Cvačka^e ; Iosune Arrastia^b ; ^d ; Ana Arrieta^b ; Pavel Dra&scaron ; ar^a ; José ; I. Miranda^f ; Fernando P. Cossí ; o^b ; ^d ; ^{fp.cossio@ehu.es" class="auth_mail" title="E-mail the corresponding author}
• 关键词：Cyclopropanation ; Catalysis ; Kinetic analysis ; Dendrimers ; Molecular dynamics ; DOSY
• 刊名：Tetrahedron
• 出版年：2016
• 出版时间：25 February 2016
• 年：2016
• 卷：72
• 期：8
• 页码：1120-1131
• 全文大小：2711 K

文摘

Experimental and computational studies on dendrimers possessing a Fe(porphyrin) catalytic core and polyether dendritic arms show that these macromolecules promote efficiently the (2+1) cycloaddition between a model alkene and diazomethane. The reaction is kinetically efficient and competitive with smaller catalysts. Lower generations of dendrimers exhibit a normal hyperbolic kinetic behaviour, whereas third- and fourth-generation dendrimers show a sigmoidal kinetic profile, compatible with cooperative effects most likely due to aggregation phenomena. This behaviour resembles that observed for Fe(porphyrin) containing biomolecules such as cytochromes and haemoglobin.