Synthesis of Cyclic Alkenyl Dimethylsiloxanes from Alkynyl Benzyldimethylsilanes and Application in Polyene Synthesis
作者:Haraldur G. Gudmundsson、Christian J. Kuper、Damien Cornut、Felix Urbitsch、Bryony L. Elbert、Edward A. Anderson
DOI:10.1021/acs.joc.9b01664
日期:2019.11.15
Cyclic dimethylalkenylsiloxanes, useful motifs for (Z)-selective Hiyama cross-coupling, are accessed from alkynyl benzyldimethylsilanes featuring adjacent allylic or homoallylic oxygen substituents by semihydrogenation/debenzylation/cyclization. While formation of 5- and 6-membered rings can be achieved from the free alcohols using fluoride or silanolate, allylic acetate precursors to 5-membered rings
Stereo- and Regiospecific Cu-Catalyzed Cross-Coupling Reaction of Vinyl Iodides and Thiols: A Very Mild and General Route for the Synthesis of Vinyl Sulfides
作者:M. Shahjahan Kabir、Michael L. Van Linn、Aaron Monte、James M. Cook
DOI:10.1021/ol801149n
日期:2008.8.7
A mild and efficient method for the copper-catalyzed formation of vinylic carbon-sulfur bonds has been developed. The desired vinyl sulfides are obtained in good to excellent yields, with full retention of stereochemistry. This method is particularly noteworthy given its mild reaction conditions, simplicity, and generality, as well as low cost of the catalyst system.
Second-Generation Synthesis of the Northern Fragment of Mandelalide A: Role of π-Stacking on Sharpless Dihydroxylation of <i>cis</i>-Enynes
作者:Ankan Ghosh、Alexander C. Brueckner、Paul Ha-Yeon Cheong、Rich G. Carter
DOI:10.1021/acs.joc.9b01153
日期:2019.7.19
asymmetric and diastereomeric dihydroxylation of cis-enynes is disclosed. The use of neighboring, electron-rich benzoateesters proved key to the success of this process. Density functional theory study suggests that the substrate benzoateester group rigidifies the dihydroxylation transition states by forming a favorable π-stacking interaction in both Major-TS and Minor-TS. The energetic preference for
A Very Active Cu-Catalytic System for the Synthesis of Aryl, Heteroaryl, and Vinyl Sulfides
作者:M. Shahjahan Kabir、Michael Lorenz、Michael L. Van Linn、Ojas A. Namjoshi、Shamim Ara、James M. Cook
DOI:10.1021/jo1004179
日期:2010.6.4
facilitated the Cu-catalyzed cross-coupling reactions of alkyl, aryl, or heterocyclic thiols with either alkyl, aryl, heterocyclic, or substitutedvinylhalides. This new catalytic system promoted the mild and efficient stereo- and regiospecific synthesis of biologically important vinylsulfides. The yields obtained using electron-rich substitutedvinylsulfides with this catalyst system are generally
Palladium-catalysed ligand-free reductive Heck cycloisomerisation of 1,6-en-α-chloro-enamides
作者:Yangyang Hou、Jing Ma、Hongyi Yang、Edward A. Anderson、Andy Whiting、Na Wu
DOI:10.1039/c9cc00537d
日期:——
The first example of an intramolecular hydroarylation of 1,6-en-α-chloro-enamides was achieved by a palladium-catalysed ligand-free reductive Heck cycloisomerisation with no competing Heck-cyclised by-product.