Palladium-catalyzed asymmetric allylations of chiral enamines bearing phosphine functionality. Effects of anionic counterparts of allylating reagents on asymmetric induction
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.
Asymmetric induction reactions. IV. Palladium-catalyzed asymmetric allylations of chiral enamines bearing phosphine groups.
作者:Kunio HIROI、Jun ABE
DOI:10.1248/cpb.39.616
日期:——
The palladium-catalyzed asymmetric allylations of chiral enamines, derived from (S)-2-(diphenylphosphinomethyl)pyrrolidine, produced optically active α-allyl carbonyl compounds in high optical yields. The phosphino group in the chiral enamines presumably serves as a chiral ligand in these palladium-catalyzed reactions. In the transition states of π-allylpalladium complexes coordinated with the intramolecular phosphine group, the anionic counterparts or allylating reagents are considered to play an important role in controlling of the grade of the enantioselectivity.
Counterion-Enhanced Pd/Enamine Catalysis: Direct Asymmetric α-Allylation of Aldehydes with Allylic Alcohols by Chiral Amines and Achiral or Racemic Phosphoric Acids
catalytic procedure for the direct asymmetric α-allylation of branched aldehydes. The use of simple chiralamines and easily prepared achiral or racemic phosphoric acids, together with a suitable Pd-source resulted in a highly active and enantioselectivecatalyst system for the allylation of various α-branched aldehydes with different allylic alcohols. The reported procedure could provide an easy access to
Asymmetric α-Allylation of Aldehydes with Alkynes by Integrating Chiral Hydridopalladium and Enamine Catalysis
作者:Yong-Liang Su、Lu-Lu Li、Xiao-Le Zhou、Zhen-Yao Dai、Pu-Sheng Wang、Liu-Zhu Gong
DOI:10.1021/acs.orglett.8b00740
日期:2018.4.20
A palladium-catalyzed asymmetric α-allylation of aldehydes with alkynes has been established by integrating the catalysis of enamine and chiral hydridopalladium complex that is reversibly formed from the oxidative addition of Pd(0) to chiral phosphoric acid. The ternary catalyst system, consisting of an achiral palladium complex, a primary amine, and a chiral phosphoric acid allows the reaction to
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