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.
Organocatalytic Asymmetric α-Allylation and Propargylation of α-Branched Aldehydes with Alkyl Halides
作者:Masanori Yoshida
DOI:10.1021/acs.joc.1c01394
日期:2021.8.6
Enantioselective α-allylation and -propargylation of α-branched aldehydes with alkyl halides was successfully performed using a chiral primary amino acid organocatalyst. This alkylation reaction, involving the generation of a chiral quaternary carbon stereocenter, proceeded smoothly in a mildly basic aqueous solution of potassium hydrogen carbonate to furnish α-allylated or -propargylated aldehydes
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