57049-58-8Relevant academic research and scientific papers
A mild method for generation of o-quinone methides under basic conditions. the facile synthesis of trans-2,3-dihydrobenzofurans
Chen, Mu-Wang,Cao, Liang-Liang,Ye, Zhi-Shi,Jiang, Guo-Fang,Zhou, Yong-Gui
, p. 1660 - 1662 (2013/03/14)
A novel and efficient method for the generation of o-quinone methide intermediates was developed from the readily available 2-tosylalkylphenols under the mild basic conditions, and their reactions with sulfur ylides were investigated for the stereoselective synthesis of trans-2,3-dihydrobenzofurans. The Royal Society of Chemistry 2013.
Reaction of benzyne with styrene oxide: Insertion of arynes into a C-O bond of epoxides
Beltrán-Rodil, Sandra,Pe?a, Diego,Guitián, Enrique
, p. 1308 - 1310 (2008/02/07)
Benzyne inserts into one of the C-O bonds of styrene oxide to form a dihydrobenzofuran as the major product together with five other reaction products. A detailed study of the reaction mixture clarified an intriguing forty-year-old personal communication from Stiles and Haag. Georg Thieme Verlag Stuttgart.
Generation and Reactions of 2-Alkoxydiphenylcarbenes in Fluid Solution and Rigid Matrices
Tomioka, Hideo,Nakanishi, Keisaku,Izawa, Yasuji
, p. 465 - 470 (2007/10/02)
Irradiation of 2-alkoxydiphenyldiazomethanes 1 in cyclohexane at room temperature produced 3-phenyldihydrobenzofurans 3 presumably as a result of intramolecular C-H insertion of 2-alkoxydiphenylcarbenes 2.Irradiation of compounds 1 in cyclohexane matrix at -196 deg C gave intermolecular C-H insertion products 4 at the expense of benzofurans 3.The formation of products 4 is explicable in terms of H-atom tunnelling to the triplet state of carbenes 2, followed by coupling of the resulting radical pairs.Product ratios 3:4 were somewhat sensitive to the bulk of the alkoxy group at the 2-position.This can be explained in terms of the matrix effect on the relative population of the rotational isomers of the carbene 2.Irradiation of compounds 1 in methanol at room temperature afforded O-H insertion products 5 almost exclusively, whereas irradiation in methanol matrix at -196 deg C gave C-H insertion products 6 along with other products 3 and 5.
Buttressing Effect in Carbene Chemistry. Effect of 3-Alkyl Groups on the Reactions of 2-Alkoxydiphenylcarbenes
Tomioka, Hideo,Kimoto, Kohji,Murata, Hiroshi,Izawa, Yasuji
, p. 471 - 477 (2007/10/02)
Irradiation of 2-methoxydiphenyldiazomethane 1a in diethyl ether at 10 deg C gave 3-phenyldihydrobenzofuran 3a along with a small amount of the ether adduct 4a, which became the major product when the irradiation was carried out in the ether matrix at -196 deg C.The reaction patterns were dramatically changed as an alkyl group was introduced into the 3-position of substrates 1.Thus, irradiation of 2-methoxy-3-alkyldiphenyldiazomethanes 1b-d in diethyl ether either at 10 deg C or at -196 deg C afforded the corresponding benzofurans 3b-d at the complete expense of the ether adducts 4b-d.The results are nicely explained in terms of the buttressing effect of the 3-alkyl group, which prevents the 2-methoxy group from lying in the plane of the phenyl ring in the precursor molecules and assists the methoxy group in rotating around the C-O bond toward the carbene centre after elimination of N2.Generation of carbenes 2 in methanol at 10 deg C produced O-H insertion adducts 5 as the major product at the expense of benzofurans 3.The ether 5a was formed as a major product in the reaction of carbene 2a with the alcohol matrix at -196 deg C, but the benzofurans 3 became the major product in the irradiation of substrates 1b-d in methanol matrix at -196 deg C.The results are again explicable in terms of the buttressing effect of 3-alkyl substituents on the relative populations of thew rotational isomers of the carbenes 2.The effect of the 3-alkyl group on the reaction of 2,2',5'-trimethoxydiphenylcarbenes 7 which form two kinds of intramolecular C-H insertion products 8 and 9 were studied and the results are again discussed in terms of the buttressing effect.
