01722nas a2200253 4500008004100000022001400041245012000055210006900175260000800244300001200252490000700264520084500271653002101116653002601137653002201163653002001185653001101205100002301216700002201239700002301261700002401284700002901308856013101337 2018 eng d a1319-610300aCascade synthesis of dihydrobenzofuran via claisen rearrangement of allyl aryl ethers using FeCl 3 /MCM-41 catalyst0 aCascade synthesis of dihydrobenzofuran via claisen rearrangement cMAY a396-4040 v223 a
Dihydrobenzofuran as one of the active ingredients of the naturally occurring motif is synthesized by using in situ generation of ortho allyl phenols. Aryl allyl ethers on reacting with catalytic amounts of non noble metal iron (III) chloride supported on MCM-41 under moderate reaction conditions yield dihydrobenzofuran. First step via Claisen rearrangement gives ortho allyl phenol followed by its in situ cyclization to yield dihydrobenzofuran in very good yields. Both Lewis as well as Brønsted acidity of the catalyst as evidenced by Py-FTIR studies was found to catalyze the cascade synthesis of dihydrobenzofuran. The scope of the present strategy was successfully demonstrated for several substrates with varying electronic effects for the synthesis of corresponding dihydrobenzofuran with high yields in a range of 71-86%.
10aAryl allyl ether10aClaisen rearrangement10aDihydrobenzofuran10aFerric chloride10aMCM-411 aSakate, Sachin, S.1 aShinde, Suhas, H.1 aKasar, Gayatri, B.1 aChikate, Rajeev, C.1 aRode, Chandrashekhar, V. uhttp://library.ncl.res.in/content/cascade-synthesis-dihydrobenzofuran-claisen-rearrangement-allyl-aryl-ethers-using-fecl-3-mcm