19873-22-4Relevant academic research and scientific papers
Highly syn selective addition of aqueous HBr to hydrophobically shielded arylalkynes
Knorr, Rudolf,Rossmann, Eva C.,Knittl, Monika,B?hrer, Petra
supporting information, p. 5332 - 5338 (2014/12/10)
Hydrophobically shielded alkynes HCC-aryl, carrying 2,6-di- and 2,4,6-tri-tert-butylphenyl as the aryl group, can add aqueous HBr on heating in moist chloroform solutions to produce pure H2CC(-Br)-aryl (isolated yields 96%, no hydrolysis). Employment of DCC-aryl furnished initially only the E stereoisomer of DHCC(-Br)-aryl (stereospecific syn addition), which was slowly both dedeuteriated and partially transformed to the Z stereoisomer by HBr. The strongly retarded HBr addition to H3C-CC-aryl in moist chloroform produced again more E than Z product, whereas a thermodynamic E/Z ratio of 10:87 was found in moist acetic acid. Substitution of Br by LiSnMe3produced H2CC(-SnMe3)-aryl with well resolved long range 119Sn NMR coupling constants.
Highly syn selective addition of aqueous HBr to hydrophobically shielded arylalkynes
Knorr, Rudolf,Rossmann, Eva C.,Knittl, Monika,B?hrer, Petra
, p. 5332 - 5338 (2014/07/08)
Hydrophobically shielded alkynes HC≡C-aryl, carrying 2,6-di- and 2,4,6-tri-tert-butylphenyl as the aryl group, can add aqueous HBr on heating in moist chloroform solutions to produce pure H2C=C(-Br)-aryl (isolated yields 96%, no hydrolysis). Em
2,2′,4,4′,6-Penta-tert-butylbenzil: An unexpected product in the attempted coupling of tri-tert-butylbenzoyl chloride with magnesium-magnesium iodide
Frey, Joseph,Rappoport, Zvi
, p. 1395 - 1397 (2007/10/03)
Reduction of 2,4,6-tri-tert-butylbenzoyl chloride with Mg-MgI2 in 1:1 diethyl ether-benzene under ultrasonic irradiation gives the hexa-tert-butyl-benzil and -benzoin and also 2,2′,4,4′,6-penta-penta-tert butylbenzil. Possible mechanisms for the loss of the Bu′ group are discussed.
