尽管迈克尔加成反应是一种众所周知且应用广泛的反应,但具有成本效益、不含金属且易于制备的有机催化剂仍然很少见。开发了一种手性、双功能、( R , R )-1,2-二苯基乙二胺衍生的硫脲有机催化剂,并将其应用于中性条件下硝基烯烃的不对称迈克尔加成。通常,氟取代的硫脲催化剂在中性条件下表现出高化学产率和对映选择性。温和的反应对许多官能团具有耐受性,并提供了良好的产率,以及迈克尔加合物的高非对映和对映选择性。通过合成生物活性化合物 ( R )-Phenibut 证明了转化的效用。
C3-symmetricchiraltrisimidazoline was designed and synthesized as a new entry of organocatalyst with the concept of constructing C3-symmetric molecules with three C2-symmetric chiral components, and the application of this novel catalyst to asymmetric conjugate addition of β-ketoesters to nitroolefins was described.
Asymmetric Michaeladdition of β-ketoesters with trans-β-nitroolefins using chiral amino amide organocatalyst was tried and afforded synthetically useful chiral Michael adducts in both excellent c...
A highly enantioselective Michael addition of β‐keto esters to nitroolefins was carried out using newly designed optically active 2‐azanorbornane‐based aminoalcohol organocatalysts to produce the corresponding chiral Michael adducts in good chemical yields (up to 99 %) and stereoselectivities (up to dr = 91:9, up to 91 % ee).
Hexafluorobenzene: a powerful solvent for a noncovalent stereoselective organocatalytic Michael addition reaction
作者:Alessandra Lattanzi、Claudia De Fusco、Alessio Russo、Albert Poater、Luigi Cavallo
DOI:10.1039/c2cc17488j
日期:——
A dramatic enhancement of the diastereo- and enantioselectivity in the nitro-Michaeladdition reaction organocatalysed by a commercially available alpha,alpha-L-diaryl prolinol was disclosed when performing the reaction in unconventional hexafluorobenzene as a medium. DFT calculations were performed to clarify the origin of stereoselectivity and the role of C(6)F(6).
Fine‐Tunable Organocatalysts Bearing Multiple Hydrogen‐Bonding Donors for Construction of Adjacent Quaternary and Tertiary Stereocenters via a Michael Reaction
作者:Zhi‐Hai Zhang、Xiu‐Qin Dong、Dong Chen、Chun‐Jiang Wang