catalytic methods for the oxidative furan-recyclizations remain scarcely investigated. Given this, we report a means of manganese-catalyzed oxidations of furan with low loading, achieving the Achmatowiczrearrangement in the presence of hydrogen peroxide as an environmentally benign oxidant under mild conditions with wide functional group compatibility.
A method for producing a furfuryl alcohol useful as an intermediate for producing agricultural chemicals, medicines, perfumes, etc., represented by the general formula (I), ##STR1## wherein R.sub.1 represents a hydrogen atom or a methyl group, and R.sub.2 represents an allyl or propargyl group, which comprises reacting a furfural represented by the general formula (II), ##STR2## wherein R.sub.1 has the same meaning as described above, with a halogen compound represented by the general formula, X--R.sub.2 wherein X represents a halogen atom and R.sub.2 has the same meaning as described above, in water or a water/organic solvent mixed solvent in the presence of at least one organic quaternary ammonium salt selected from the group consisting of tetra(C.sub.2 -C.sub.5 alkyl)amonium halide, benzyltri (C.sub.2 -C.sub.3 alkyl)ammonium chloride, dodecyltrimethylammonium bromide and cetyltrimethylammonium chloride as well as an inorganic ammonium salt and zinc.
A novel copper‐catalyzed one‐pot functionalization of homopropargylic alcohols that involves trifluoromethylation, aryl migration, and formation of a carbonyl moiety has been developed. This reaction constitutes the first direct conversion of homopropargylic alcohols into CF3‐containing 3‐butenal or 3‐buten‐1‐one derivatives in a regioselective manner. Mechanistic studies indicate that the 1,4‐aryl
Gold(I)-Catalyzed Formation of Benzo[b]furans from 3-Silyloxy-1,5-enynes
作者:A. Stephen K. Hashmi、Weibo Yang、Frank Rominger
DOI:10.1002/anie.201100989
日期:2011.6.14
Sport of kings: A new gold(I)‐catalyzed transformation has been developed that occurs under mild conditions and proceeds by an expected substituent “castling” (see red and blue circles in scheme) to give efficient access to benzo[b]furans from the easy to obtain 3‐silyloxy‐1,5‐enynes (IPr=N,N′‐bis(2,6‐diisopropylphenyl)imidazol‐2‐ylidene, NTf2=bis(trifluoromethylsulfonylimide).
国王运动:已经开发了一种新的金(I)催化的转化,该转化在温和的条件下发生,并通过预期的取代基“浇铸”进行转化(请参见方案中的红色和蓝色圆圈),以有效地从中获得苯并[ b ]呋喃容易获得的3-甲硅烷氧基-1,5-炔烃(IPr = N,N'-双(2,6-二异丙基苯基)咪唑-2-亚烷基,NTf 2 =双(三氟甲基磺酰亚胺)。