Chem. J. Chinese Universities ›› 2021, Vol. 42 ›› Issue (9): 2805.doi: 10.7503/cjcu20210215

• Organic Chemistry • Previous Articles     Next Articles

Sc(OTf)3 Catalyzed 1,6-Conjugate Allylation of δ-CN p-QMs: Synthesis of Allyl Substituted Diarylacetonitrile Compounds

HU Chuanchuan1, PANG Jingxiang3, HE Chuangchuang1, LI Wei1(), SUN Shutao2()   

  1. 1.Department of Pharmaceutical Analysis,School of Pharmacy,Shandong University of Traditional Chinese Medicine,Jinan 250355,China
    2.School of Chemistry and Chemical Engineering,Shandong University,Jinan 250100,China
    3.Shandong Medicinal Biotechnology Centre,Institute of Materia Medica,Shandong First Medical University,Shandong Academy of Medical Sciences,Jinan 250000,China
  • Received:2021-03-30 Online:2021-09-10 Published:2021-09-08
  • Contact: LI Wei,SUN Shutao E-mail:liwei6911@163.com;shutaosun@sdu.edu.cn
  • Supported by:
    the Natural Science Foundation of Shandong Province, China(ZR2020QB018);the China Postdoctoral Science Foundation(2019M662322)

Abstract:

Sakurai allylation is one of the most important methods for the construction of carbon-carbon bonds, which shows a wide range of applications in the synthesis of bioactive molecules. The addition of allyl silane to carbonyl and imine groups, which could be used to prepare homoallyl alcohols or homoallylamines, has been well studied. Similarly, the addition of allyl silane to αβ-unsaturated carbonyl compounds has also been widely explored. However, the 1,6-addition of allyl silane to diketene compounds have always been a major challenge in this field, and current research is still mainly mediated by stoichiometric strong Lewis acid. In recent years, p-quinone methides(p-QMs), as a special electrophilic reagent, has attracted wide attention of synthetic chemists and plays a very important role in the synthesis of natural products and pharmaceutical chemistry. The unique conjugated structure of diketene in the skeleton of p-QMs, and the driving force of aromatization after nucleophile addition lays a foundation for its high regioselectivity 1,6-conjugated addition. We envision that the allylation of p-QMs by 1,6-conjugate addition would afford allyl substituted diarylmethane compounds with potential biological activity. This paper reported the Sc(OTf)3 catalyzed 1,6-conjugate addition of δ-cyano-δ-aryl substituted p-QMs with allyltrimethylsilane. A series of allyl substituted diaryl acetonitriles with quaternary centers was prepared. The operation of this reaction was simple and the reaction condition was mild. The results showed good substrate scope and functional group compatibility. At the same time, the synthetic potential of the method was demonstrated by the derivation of nitrile and allyl groups, respectively.

Key words: 1, 6-Conjugate addition, Allylation, p-Quinone methide, Scandium trifluoromethanesulfonate, Catalysis

CLC Number: 

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