30860-09-4Relevant academic research and scientific papers
Photolysis of 1-Bromo-2,2-bis(p-methoxyphenyl)ethene in solution
Johnen, Norbert,Schnabel, Wolfram,Kobayashi, Shinjiro,Fouassier, Jean-Pierre
, p. 1385 - 1390 (1992)
UV irradiation (λinc = 254 nm) of 1-bromo-2,2-bis(p-methoxyphenyl)ethene (AAHVB) in acetonitrile solution results in its decomposition: Φ(-AAHVB) = 0.18 both in the absence and presence of O2.Apart from the isomers the main photoproducts are 1,2-bis(p-methoxyphenyl)ethine (P-2) and HBr (Φ ca. 0.1).Flash photolysis studies in acetonitrile, dichloromethane and n-hexane solution at 266 nm revealed that P-2 is formed with a halflife of less than a few ns via a singlet route involving vinyl cations which rapidly rearrange and split off protons.Part of the vinyl cations decay via a differnet route forming an ionic species with an optical absorption band at ca. 350 nm.The decay of the latter is not correlated with the formation of P-2.This ionic species probably results from an interaction of vinyl cations with solvent or AAHVB.AAHVB quenches triplet states of various compounds X (e.g. benzophenone, chrysene, benzil, pyrene) provided that ET(X) >200 kJ mol-1.The energy transfer from these compounds to AAHVB does not result in the formation of P-2 or vinyl cations.
Iridium-Catalyzed Hydrochlorination and Hydrobromination of Alkynes by Shuttle Catalysis
Yu, Peng,Bismuto, Alessandro,Morandi, Bill
supporting information, p. 2904 - 2910 (2020/01/25)
Described herein are two different methods for the synthesis of vinyl halides by a shuttle catalysis based iridium-catalyzed transfer hydrohalogenation of unactivated alkynes. The use of 4-chlorobutan-2-one or tert-butyl halide as donors of hydrogen halides allows this transformation in the absence of corrosive reagents, such as hydrogen halides or acid chlorides, thus largely improving the functional-group tolerance and safety profile of these reactions compared to the state-of-the-art. This method has granted access to alkenyl halide compounds containing acid-sensitive groups, such as tertiary alcohols, silyl ethers, and acetals. The synthetic value of those methodologies has been demonstrated by gram-scale synthesis where low catalyst loading was achieved.
