147918-36-3Relevant articles and documents
Decarboxylative Alkynylation
Smith, Joel M.,Qin, Tian,Merchant, Rohan R.,Edwards, Jacob T.,Malins, Lara R.,Liu, Zhiqing,Che, Guanda,Shen, Zichao,Shaw, Scott A.,Eastgate, Martin D.,Baran, Phil S.
, p. 11906 - 11910 (2017/09/06)
The development of a new decarboxylative cross-coupling method that affords terminal and substituted alkynes from various carboxylic acids is described using both nickel- and iron-based catalysts. The use of N-hydroxytetrachlorophthalimide (TCNHPI) esters is crucial to the success of the transformation, and the reaction is amenable to in situ carboxylic acid activation. Additionally, an inexpensive, commercially available alkyne source is employed in this formal homologation process that serves as a surrogate for other well-established alkyne syntheses. The reaction is operationally simple and broad in scope while providing succinct and scalable avenues to previously reported synthetic intermediates.
Synthese der Theonelladine A, B, C, D und von Niphatesin A
Teubner, Achim,Gerlach, Hans
, p. 161 - 166 (2007/10/02)
The pyridine alkaloids theonelladine A-D (1-4) and niphatesine (5) of marine origin have been synthesized starting either from 3-(4,4-dibromo-3-butenyl)pyridine (6) or from 3-pyridinecarbaldehyde.Reaction of 6 with two equivalents of BuLi gave the lithiated derivative of the alkyne 7, which could be alkylated with 1-bromo-10-(tetrahydro-2-pyranyloxy)decane (8) to yield the alkynol 9 after methanolysis.Selective hydrogenation of 9 with Lindlar palladium catalyst gave (Z)-14-(3-pyridyl)-11-tetradecen-1-ol (11). - Addition of the Grignard reagent of 12-(benzyloxy)-1-bromododecane (13) to 3-pyridinecarbaldehyde gave 17, which was first oxidized (Swern) to give 18 and then reduced (Wolff-Kishner) to give 14.Hydrogenolysis of the benzyl ether 14 yielded 15.The alcohol group in 9, 11, and 15 was converted into the tosyloxy group by reaction with tosyl chloride/pyridine.Subsequent reactions of the tosylates 10, 12, and 16 either with an excess of methylamine/ethanol or of ammonia/ethanol gave the pyridine alkaloids 1-5 in high yields as p-toluenesulfonates. Key Words: Pyridines/Alkaloids/Theonelladines A-D/Niphatesine A/4-(3-Pyridyl)-1-butin.