The Origins of Enantioselectivity in Rh-Diene Complex Catalysed Arylation of Cyclohex-2-enones
作者:Silvia Gosiewska、Jevgenij A. Raskatov、Ryo Shintani、Tamio Hayashi、John M. Brown
DOI:10.1002/chem.201102421
日期:2012.1.2
Chiral diene ligands: Conjugate addition of aryl boronic acids to cyclohexenone is catalysed by Rh complexes of the simple chiral diene (S)‐bicyclo[3.3.1]nona‐2,6‐diene in unexpectedly high ee. Insight into the reasons, and more generally the TS structure and pathways with other catalysts, was explored by using density functional theory. There was a gratifyingly good agreement between calculation and
Aqueous Asymmetric 1,4-Addition of Arylboronic Acids to Enones Catalyzed by an Amphiphilic Resin-Supported Chiral Diene Rhodium Complex under Batch and Continuous-Flow Conditions
yields and with excellent enantioselectivity. The catalyst was readily recovered by simple filtration and reused 10 times without loss of its catalytic activity and enantioselectivity. Moreover, a continuous-flow asymmetric 1,4-addition in a flow reactor containing PS–PEG–diene*–Rh proceeded efficiently at 50 °C with retention of high enantioselectivity. Long-term continuous-flow asymmetric 1,4-addition
Chiral Sulfinyl-Based Olefin Ligands for Rhodium-Catalysed Asymmetric Conjugate Addition of Arylboronic Acids to Cyanoalkenes
作者:Feng Xue、Yong Zhu、Xiaolei Qi
DOI:10.3184/174751918x15287224792440
日期:2018.6
A rhodium/sulfinyl-based olefin ligand-catalysed asymmetric conjugate addition of arylboronic acids to cyanoalkenes without activation groups has been developed, where p-tolylsulfinyl-functionalised olefin ligands have been shown to be effective and with moderate enantioselectivities. This is the first example of applying chiral sulfinyl-based olefin ligands in the catalytic asymmetric addition to
Copper-Catalyzed 1,4-Addition of Organoboronates to Alkylidene Cyanoacetates: Mechanistic Insight and Application to Asymmetric Catalysis
作者:Keishi Takatsu、Ryo Shintani、Tamio Hayashi
DOI:10.1002/anie.201008196
日期:2011.6.6
In addition: A copper/N‐heterocyclic carbene(NHC)‐catalyzed 1,4‐addition of organoboronates to alkylidene cyanoacetates was developed, in which the catalytic cycle is proposed to consist of a transmetalation/insertion/ligand exchange. An effective asymmetric variant has also been achieved by the use of a chiral NHC ligand (see scheme).
Asymmetric1,4-addition of arylboronicacids to (E)-methyl 2-cyano-3-arylpropenoates proceeded in the presence of a rhodium catalyst (3 mol %) coordinated with a chiral diene ligand, (R,R)-Ph-bod*, to give high yields of the corresponding methyl 3,3-diaryl-2-cyanopropanoates with high enantioselectivity (up to 99% ee). This catalytic asymmetric transformation was applied to the asymmetric synthesis
在具有手性二烯配体(R,R)-Ph- bod *,以高对映选择性(至多99%ee)得到高产率的相应的3,3-二芳基-2-氰基丙酸甲酯。该催化不对称转化应用于(R)-托特罗定的不对称合成。