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.
nickel and chiralamine cooperative catalysis to enable a highlyenantioselectiveallylic alkylation reaction between α-branched aldehydes and a wide scope of allyl esters, allowing the all-carbon quaternary stereocenter to be accessed with excellent enantioselectivity (up to 98% ee) and structural diversity. The general synthetic applicability has been showcased by the enantioselective synthesis of
全碳四元立体中心构成了天然产物和生物活性化合物的重要组成部分。在这里,我们公开了一种镍和手性胺协同催化,使 α-支化醛和各种烯丙基酯之间发生高度对映选择性的烯丙基烷基化反应,从而以优异的对映选择性(高达 98% ee ) 和结构多样性。关键手性构件的对映选择性合成以获取 (+)-依他佐辛、(-)-aphanorphine 和其他两种生物活性化合物,展示了一般合成适用性。
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,
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
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