Highly effective tandem hydroformylation–acetalization of olefins using a long-life Brønsted acid–Rh bifunctional catalyst in ionic liquid–alcohol systems
作者:Xin Jin、Kun Zhao、Feifei Cui、Fangfang Kong、Qiangqiang Liu
DOI:10.1039/c3gc41231h
日期:——
A robust and highly effective tandem hydroformylationâacetalization of olefins using a Brønsted acidâRh bifunctional catalyst (ARBC) in ionic liquidâalcohol systems is reported. The key feature of the ARBC is its use of a zwitterionic phosphine ligand bearing an amino acid tag. This novel ARBC shows an excellent catalytic efficiency and a long service life without a significant drop in both the hydroformylation efficiency and the acetalization efficiency or Rh loss for more than seventeen cycles. We believe that the long-term high activity and acetal selectivity mainly benefit from the synergy between the acidic active site and the Rh active site on the ARBC and the highly effective immobilization and recycling of ARBC in ionic liquidâalcohol systems due to the strong affinity of ARBC for the ionic liquid.
IPy2BF4-Mediated Rearrangements of 1,2-Difunctionalized Compounds and Olefins
作者:Francisco J. Fañanás、Mónica Álvarez-Pérez、Félix Rodríguez
DOI:10.1002/chem.200500070
日期:2005.10.7
Acetal derivatives are easily obtained from 1,2-difunctionalizedcompounds by a new reaction mediated by IPy2BF4 with a mechanism based on a 1,2-migration of aryl or alkyl groups. A new oxidative rearrangement reaction of olefins is also described. Moreover, when this metal-free protocol is applied to cyclic olefins, interesting ring-contraction reactions are observed. The new methodologies described