Chiral Counteranions in Asymmetric Transition-Metal Catalysis: Highly Enantioselective Pd/Brønsted Acid-Catalyzed Direct α-Allylation of Aldehydes
作者:Santanu Mukherjee、Benjamin List
DOI:10.1021/ja074678r
日期:2007.9.1
Pd/chiral acid-catalyzed α-allylation of α-branched aldehydes with an allyl amine as the allylating species that creates all-carbonquaternary stereogenic centers in high yields and enantioselectivities. To our knowledge, this is the first time that a chiral anionic ligand is applied for achieving asymmetric induction in a palladium-catalyzedallylicalkylation reaction.
Chiral Counteranion Strategy for Asymmetric Oxidative C(sp<sup>3</sup>)H/C(sp<sup>3</sup>)H Coupling: Enantioselective α-Allylation of Aldehydes with Terminal Alkenes
作者:Pu-Sheng Wang、Hua-Chen Lin、Yu-Jia Zhai、Zhi-Yong Han、Liu-Zhu Gong
DOI:10.1002/anie.201408199
日期:2014.11.3
The first enantioselective α‐allylation of aldehydes with terminalalkenes has been realized by combining asymmetriccounteranion catalysis and palladium‐catalyzed allylic CH activation. This method can tolerate a wide scope of α‐branched aromatic aldehydes and terminalalkenes, thus affording allylation products in high yields and with good to excellent levels of enantioselectivity. Importantly,
α-Quaternary Chiral Aldehydes from Styrenes, Allylic Alcohols, and Syngas via Multi-catalyst Relay Catalysis
作者:Jing Meng、Lian-Feng Fan、Zhi-Yong Han、Liu-Zhu Gong
DOI:10.1016/j.chempr.2018.03.010
日期:2018.5
synthesizes organic molecules, multi-catalyst relay catalysis (MCRC), based on the seamless combination of a series of catalyticreactions, has emerged as a promising strategy for achieving ideal synthesis. In such systems, each step takes place orderly and sequentially. Taken as a whole, the entire process appears indistinguishable from a common one-step reaction but provides a means for extraordinary transformations
Directα-allylation of α-branched aldehydes was successfully carried out with a readily available allyl ester by combined use of two catalytic systems: Tsuji–Trost allylation reaction with an achiral palladium complex and enamine catalysis with a chiral primary α-amino acid. A quaternary carbon stereogenic center was constructed stereoselectively to give various 2,2-disubstituted pent-4-enals in good
Heterogeneous organo/metal cooperative catalysis: One-pot immobilization of Pd(PPh3)4 and chiral phosphoric acid to hollow mesoporous polystyrene nanospheres for efficient asymmetric α-allylation of aldehydes
作者:Mingyang Xie、Wenyan Tian、Xuebing Ma
DOI:10.1016/j.apcata.2024.119905
日期:2024.8
The widely used combinations of palladium catalysts and chiral phosphoricacids face with the problems of cooperative catalysis and low-cost immobilization of binary catalysts in heterogeneous catalysis, due to the significant decline in the freedom of anchored catalysts. In this paper, the one-pot immobilization of both chiral phosphoricacid (TRIP) and Pd(PPh) to hollow mesoporous polystyrene nanospheres