Ynamide Carbopalladation: A Flexible Route to Mono‐, Bi‐ and Tricyclic Azacycles
作者:Craig D. Campbell、Rebecca L. Greenaway、Oliver T. Holton、P. Ross Walker、Helen A. Chapman、C. Adam Russell、Greg Carr、Amber L. Thomson、Edward A. Anderson
DOI:10.1002/chem.201501710
日期:2015.9
Bromoenynamides represent precursors to a diversity of azacycles by a cascade sequence of carbopalladation followed by cross‐coupling/electrocyclization, or reduction processes. Full details of our investigations into intramolecular ynamidecarbopalladation are disclosed, which include the first examples of carbopalladation/cross‐coupling reactions using potassium organotrifluoroborate salts; and an
MPTGs: Thioglycoside Donors for Acid-Catalyzed <i>O</i>-Glycosylation and Latent-Active Synthetic Strategies
作者:Shaofu Du、Justin R. Ragains
DOI:10.1021/acs.orglett.8b03958
日期:2019.2.15
range of alcohol acceptors in the presence of 10 mol % of triflic acid at room temperature. Particularly encouraging is the reactivity of MPTGs toward unreactive acceptors. MPTGs can be synthesized from the requisite vinyl bromides using the Suzuki reaction, and this chemistry can be leveraged toward a “latent-active” strategy for oligosaccharide synthesis.
Tandem radical nitrile transfer-cyclization reactions of 1,3-dioxane-4-nitriles: Synthesis of spirocyclic systems
作者:Scott D. Rychnovsky、Sonja S. Swenson
DOI:10.1016/s0040-4020(97)01030-2
日期:1997.12
Reduction of remote halogen substituents with n-Bu3SnH leads to efficient 1,4- and 1,5-nitrile transfer from 1,3-dioxane-4-nitriles and subsequent stereoselective reduction. These radical-transfer reactions provide a mild alternative to the Li/NH3 reductive decyanation previously used to generate syn-1,3-diols from 1,3-dioxane-4-nitriles. Compounds containing appropriate unsaturation undergo subsequent radical cyclization reactions to give spirocyclic products. (C) 1997 Elsevier Science Ltd.