139016-31-2Relevant academic research and scientific papers
Catalytic Regio- and Enantioselective Proton Migration from Skipped Enynes to Allenes
Wei, Xiao-Feng,Wakaki, Takayuki,Itoh, Taisuke,Li, Hong-Liang,Yoshimura, Takayoshi,Miyazaki, Aya,Oisaki, Kounosuke,Hatanaka, Miho,Shimizu, Yohei,Kanai, Motomu
supporting information, p. 585 - 599 (2019/03/11)
Chiral allenes are highly valuable as versatile synthetic intermediates and core skeletons of various functional organic molecules. Despite marked recent advances, the straightforward catalytic enantioselective synthesis of hydrocarbon allenes from readil
Alkynyl?B(dan)s in Various Palladium-Catalyzed Carbon?Carbon Bond-Forming Reactions Leading to Internal Alkynes, 1,4-Enynes, Ynones, and Multiply Substituted Alkenes
Tani, Tomohiro,Sawatsugawa, Yuuki,Sano, Yusuke,Hirataka, Yo,Takahashi, Naomi,Hashimoto, Sadahiro,Sugiura, Tetsuya,Tsuchimoto, Teruhisa
supporting information, p. 1815 - 1834 (2019/03/07)
It was found that the C(sp)?B(dan) bond of alkynyl?B(dan)s can be directly used for palladium-catalyzed carbon?carbon bond-forming reactions with aryl(alkenyl) halides and allylic carbonates as electrophiles, thus delivering unsymmetrical internal alkynes and unconjugated 1,4-enynes, respectively. With acyl chlorides as electrophiles, ynone synthesis is also promoted by a palladium catalyst with the assistance of a copper co-catalyst. These reactions can be achieved as more convenient one-pot reactions, without isolating the alkynyl?B(dan) formed in situ by the zinc-catalyzed dehydrogenative borylation of alkynes with HB(dan). In addition to direct C(sp)?B(dan) bond transformations, the C≡C bond in an alkynyl?B(dan) proved to be a promising scaffold for the construction of a multisubstituted alkene, which is synthesized by diboration of the C≡C?B(dan) moiety, leading to a triborylalkene followed by iterative regio- and stereoselective Suzuki?Miyaura cross-coupling reactions. As one example, the synthesis of the ethene with four different aryl groups, p-MeC6H4, p-MeOC6H4, p-NCC6H4, and p-F3CC6H4, was attained in high overall yield of 64% in six steps starting from the terminal alkyne, p-MeC6H4C≡CH. Besides these synthetic applications of the alkynyl?B(dan), the scope of the alkynyl substrate in the zinc-catalyzed dehydrogenative borylation was expanded to enhance the reliability as a provider of the alkynyl?B(dan). Consequently, 42 alkynes were found to participate in the dehydrogenative borylation as substrates; these are alkyl-, alkenyl-, aryl-, heteroaryl-, ferrocenyl-, silyl-, and borylalkynes, with or without a variety of functional groups. Lastly, a new method for preparing HB(dan), as a sulfide-free, cost-saving, and reaction-time-saving route, is disclosed. (Figure presented.).
Palladium-Catalyzed Synthesis of Alkynes via a Tandem Decarboxylation/Elimination of (E)-Enol Triflates
Munteanu, Charissa,Frantz, Doug E.
supporting information, p. 3937 - 3939 (2016/08/30)
A mild catalytic synthesis of alkynes via a tandem Pd-catalyzed decarboxylation/elimination of enol triflates is described. Key attributes of the method include readily available starting materials, broad functional group tolerance, and the ability to access terminal, internal, and halogenated alkynes. The preliminary scope of the reaction is demonstrated on 25 different examples with yields ranging from 63% to 96%.
11,12-oxidoarachidonic acid derivatives and methods of their use in treating dry eye disorders
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Page/Page column 7-9, (2008/06/13)
11,12-Oxidoarachidonic acid derivatives and methods of their use for treating dry eye are disclosed.
