Sc(OTf)_(3)催化δ⁃腈基对亚甲基苯醌的1,6⁃共轭烯丙基化:烯丙基二芳基乙腈类化合物的合成

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

将三氟甲烷磺酸钪[Sc(OTf)_(3)]用于催化δ-腈基-δ-芳基取代的对亚甲基苯醌与烯丙基硅烷的1,6-共轭加成反应,快速制备了一系列含有四级碳中心的烯丙基取代二芳基乙腈类化合物.该反应操作简单、条件温和,具有了良好的底物范围和官能团兼容性,同时腈基和烯丙基可进行后期衍生化,展示出良好的适用性.

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 toα,β-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 ofδ-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.