6051-52-1Relevant articles and documents
[Pd]-Catalyzedpara-selective allylation of phenols: access to 4-[(E)-3-aryl/alkylprop-2-enyl]phenols
Chinnabattigalla, Sreenivasulu,Choudhury, Aditya,Gedu, Satyanarayana
supporting information, p. 8259 - 8263 (2021/10/12)
4-[(E)-3-Arylprop-2-enyl]phenols are omnipresent scaffolds and constitute natural products and biologically significant compounds. Obtusastyrene and obtustyrene are two such phenolic-based natural products isolated fromDalbergia retusa. The development of strategies based on a site-selective allylation, particularly protecting group-free substrates and non-activated coupling agents, is indispensable in organic synthesis. Herein, we present a highly regioselective [Pd]-catalyzedpara-allylation of phenols using simple, inactivated allylic alcohols as allylating coupling partners. Notably, this strategy is successful in open-air and under mild reaction conditions. Besides, the efficacy of the present protocol was demonstrated by the direct synthesis of obtusastyrene and obtustyrene.
Cobalt-Catalyzed Diastereo- And Enantioselective Reductive Allyl Additions to Aldehydes with Allylic Alcohol Derivatives via Allyl Radical Intermediates
Wang, Lei,Wang, Lifan,Li, Mingxia,Chong, Qinglei,Meng, Fanke
supporting information, p. 12755 - 12765 (2021/08/30)
Catalytic generation of ambiphilic π-allyl-metal complexes and their utility in enantioselective transformations constitutes a powerful approach for introduction of allyl groups to a molecule. Herein an unprecedented cobalt-catalyzed highly site-, diastereo-, and enantioselective protocol for stereoselective formation of nucleophilic allyl-Co(II) complexes followed by addition to aldehydes is presented. The reaction features diastereo- and enantioconvergent conversion of easily accessible allylic alcohol derivatives to diversified enantioenriched homoallylic alcohols with a remarkably broad scope of allyl groups that can be introduced. Mechanistic studies indicated that allyl radical intermediates were involved in this process. These new discoveries establish a new strategy for development of enantioselective transformations through capture of radicals by chiral Co complexes, pushing forward the frontier of Co complexes for enantioselective catalysis.
Regio- and Enantioselective Preparation of Chiral Allylic Sulfones Featuring Elusive Quaternary Stereocenters
Cai, Aijie,Kleij, Arjan W.
supporting information, p. 14944 - 14949 (2019/11/05)
We describe here the first general asymmetric synthesis of sterically encumbered α,α-disubstituted allylic sulfones via Pd-catalyzed allylic substitution. The design and application of a new and highly efficient phosphoramidite ligand (L10) proved to be crucial, and a wide variety of challenging allylic sulfones featuring quaternary stereocenters could be obtained in good yields and with good to excellent levels of regio- and enantioselectivities under attractive process conditions. The developed methodology employs easily accessible chemical feedstock including racemic allylic precursors and sodium sulfinates. The utility of the method is further demonstrated by the synthesis of the sesquiterpene (?)-Agelasidine A.
