16251-77-7Relevant articles and documents
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Yamamoto,S. et al.
, p. 961 - 962 (1973)
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Highly active rhodium/phosphorus catalytic system for the hydroformylation of α-methylstyrene
Zheng, Xue-Li,Zheng, Cong-Ye,Zhou, Fan-Ding,Fu, Hai-Yan,Yuan, Mao-Lin,Li, Rui-Xiang,Xu, Bin,Chen, Hua
, p. 678 - 680 (2016)
Rhodium catalyzed hydroformylation of α-methylstyrene was investigated in the presence of monodentate phosphine ligands L1-L6. We found that the phosphine with good π-acceptability could efficiently improve the activity of the α-methylstyrene hydroformylation. The big steric hindrance of α-C in α-methylstyrene enhanced the regioselectivity towards the linear aldehyde, which resulted in 3-phenylbutanal as the predominant product (>99.0%). When tris(N-pyrrolyl)phosphine (L1) modified Rh(acac)(CO)2 was employed as the catalyst, the TOF could reach up to 5786 h-1 in the α-methylstyrene hydroformylation at relatively mild conditions (110 °C, 6 MPa).
Linear Selective Hydroformylation of 2-Arylpropenes Using Water-Soluble Rh-PNP Complex: Straightforward Access to 3-Aryl-Butyraldehydes
Ru, Tong,Liang, Guanfeng,Zhang, Luyun,Ning, Yingtang,Chen, Fen-Er
, p. 5073 - 5077 (2021/11/09)
Straightforward access to 3-aryl-butyraldehydes was developed through the aqueous biphasic Rh-catalyzed hydroformylation of 2-arylpropenes using a water-soluble PNP ligand. This protocol accommodates broad substrate scope with high yields (up to 95 %) and excellent linear selectivity (>99 : 1 b/l ratio). The synthesis of rac-ar-turmerone and the gram-scale hydroformylation further demonstrated the practical nature of this method.
Optimized iminium-catalysed 1,4-reductions inside the resorcinarene capsule: achieving >90% ee with proline as catalyst
Sokolova, Daria,Tiefenbacher, Konrad
, p. 24607 - 24612 (2021/07/29)
In previous work, we demonstrated that iminium-catalysed 1,4-reductions inside the supramolecular resorcinarene capsule display increased enantioselectivities as compared to their regular solution counterparts. Utilizing proline as the chiral catalyst, enantioselectivities remained below 80% ee. In this study, the reaction conditions were optimized by determining the optimal capsule loading and HCl content. Additionally, it was found that alcohol additives increase the enantioselectivity of the capsule-catalysed reaction. As a result, we report enantioselectivities of up to 92% ee for iminium-catalysed 1,4-reductions relying on proline as the sole chiral source. This is of high interest, as proline is unable to deliver high enantioselectivities for 1,4-reductions in a regular solution setting. Investigations into the role of the alcohol additive revealed a dual role: it not only slowed down the background reaction but also increased the capsule-catalysed reaction rate.