6780-39-8Relevant articles and documents
Indium-mediated one-pot synthesis of benzoxazoles or oxazoles from 2-nitrophenols or 1-aryl-2-nitroethanones
Lee, Jung June,Kim, Jihye,Jun, Young Moo,Lee, Byung Min,Kim, Byeong Hyo
scheme or table, p. 8821 - 8831 (2009/12/26)
One-pot reduction-triggered heterocyclizations from 2-nitrophenols to benzoxazoles and from 1-aryl-2-nitroethanones to oxazoles were investigated. In the presence of indium/AcOH in benzene at reflux, 2-nitrophenols and R-C(OMe)3 (R=H, Me, Ph) produced excellent yields of corresponding benzoxazoles within an hour. Similarly, 1-aryl-2-nitroethanones and Ph-C(OMe)3 in the presence of indium/AcOH in acetonitrile transformed into the corresponding oxazoles with good yields.
115. 1,3-Dipole mit Zentralem S-Atom aus der Umsetzung von Aziden mit Thiocarbonyl-Verbindungen: Eine unerwartete MeS-Wanderung im Abfangprodukt eines 'Thiocarbonyl-aminids' mit Dithiobenzoesaeure-methylester
Mloston, Grzegorz,Romanski, Jaroslaw,Linden, Anthony,Heimgartner, Heinz
, p. 1499 - 1510 (2007/10/02)
Reaction of PhN3 with O-methyl thiobenzoate (11a) and thioacetate (11c) as well as with the dithio esters 11b, d at 80 deg C yields the corresponding imidates and thioimidates 12 (Scheme 3).The formation of 12 is rationalized by a 1,3-dipolar cycloaddition of the azide and the C=S group followed by successive elimination of N2 and S.In the three-component reaction of 11b, PhN3, and the sterically crowded thioketone 1a, 1,2,4-trithiolane 13a and 1,4,2-dithiazolidine 3a are formed in addition to 12b (Scheme 4).The heterocycles 13 and 3a are trapping products of 1a and 'thiocarbonyl-aminide' 5a and 'thiocarbonyl-amidine' 2a (Ar= Ph), respectively (Scheme 6).These 1,3-dipoles are formed as reactive intermediates.Surprisingly, in the presence of catalytic amounts of acids, the major product is the (methyldithio)cyclobutyl thioimidate of type 14 (Scheme 5), formed by an acid-catalyzed MeS migration in dithiazolidine 17.A reaction mechanism is proposed in Scheme 7.
Mechanisms of Nucleophilic Attack at Carbon-Nitrogen Double Bonds. The Reaction of Aryl N-Arylbenzimidates with Methoxide Ion
Rowe, Jeffrey E.
, p. 1259 - 1262 (2007/10/02)
Rate data for the reaction of three series of aryl N-arylbenzimidates with methoxide ion at 303 K are presented.Linear Hammett plots were obtained for each series.Solvent isotope effects have also been measured.The results are interpreted in terms of rate-determining formation of a tetrahedral intermediate, irrespective of the nature of the substituent.