96375-12-1Relevant academic research and scientific papers
Photochemical transformation of S-aryl 2-benzoylbenzothioates to 3-phenyl-3-arylthiobenzofuranones involving aryl migration
Takahashi, Masaki,Fujita, Tsutomu,Watanabe, Shoji,Sakamoto, Masami
, p. 487 - 491 (2007/10/03)
Photochemical reactions of S-aryl 2-benzoylbenzothioates 1 in solution media have been investigated. These thioesters undergo photoinduced cyclization to 3-aryl-3-arylthioisobenzofuranones 2 in yields of 14-46% upon direct irradiation. The photocyclizatio
Acylpalladation of internal alkynes and palladium-catalyzed carbonylation of (Z)-β-iodoenones and related derivatives producing γ-lactones and γ-lactams
Copéret, Christophe,Sugihara, Takumichi,Wu, Guangzhong,Shimoyama, Izumi,Negishi, Ei-Ichi
, p. 3422 - 3431 (2007/10/02)
The reaction of either an internal alkyne-organic halide mixture or (Z)-β-iodoenones with CO in the presence of a Pd-phosphine catalyst, e.g., Cl2Pd(PPh3)2, can give one of the three discrete types of compounds as the major products depending on the substrate structure and the reaction conditions. Those substrates which are convertible to (Z)-γ-oxo-α,β-unsaturated acylpalladium derivatives lacking δ-H atoms are converted to the corresponding 2-butenolides (13) in the presence of water, which serves as a H donor. Carbon monoxide most likely is the source of two electrons. Either in the absence of water (or any other suitable H source) or in the presence of some factors disfavoring the butenolide formation, the same reaction gives the corresponding dimeric product (16). Even in cases where there is an α-H atom in the α-substitutent, 1,4-elimination products (11), reported to be the major products in a related Pd-catalyzed reaction of terminal alkyne-aryl iodide mixtures with CO, were not detected. In sharp contrast, those substrates which can give rise to (Z)-γ-oxo-α,β-unsaturated acylpalladium derivatives containing δ-H atoms give, under comparable reaction conditions, enol lactones (12), i.e., (Z)-3-alkylidene-2-butenolides, contaminated with only very minor amounts of 22 even in cases where an excess (4 equiv) of water was present. The required (Z)-β-iodoenones can be readily prepared in one pot via ZrCp2-promoted cyclization of alkynes with nitriles. The ready availability of the starting compounds and the high Z stereoselectivity make the overall sequence an attractive synthetic route to 12. The courses of the Pd-catalyzed carbonylation reactions of (Z)-β-iodo-α,β-unsaturated imines 23 closely parallel the reactions of enones and produce the corresponding lactams, i.e., 24 and 25.
Preparation and ESR-Spectroscopical Investigation of Remarkably Persistent Oxoisobenzofuranyl Radicals
Kruppa, Gary,Hug, Paul,Liegard, Andre,Rist, Guenther,Nesvadba, Petr
, p. 1821 - 1831 (2007/10/02)
The synthesis of the diastereomeric 1,1'-diaryl-1,1'-bi(isobenzofuran)-3,3'(1H,1'H)-diones 3a-d starting from the readily available 2-aroylbenzoic acids 1a-d is described (Scheme 1).Of the colourless dimers 3a-d, only the sterically congested 3a and 3b di
