Rhodium-Catalyzed Oxidative C–H Allylation of Benzamides with 1,3-Dienes by Allyl-to-Allyl 1,4-Rh(III) Migration
作者:Stamatis E. Korkis、David J. Burns、Hon Wai Lam
DOI:10.1021/jacs.6b06884
日期:2016.9.21
oxidative C-H allylation of N-acetylbenzamides with 1,3-dienes is described. The presence of allylic hydrogens cis to the less substituted alkene of the 1,3-diene is important for the success of these reactions. With the assistance of reactions using deuterated 1,3-dienes, a proposed mechanism is provided. The key step is postulated to be the first reported examples of allyl-to-allyl 1,4-Rh(III) migration
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
Synthesis of Enantioenriched Allylic Silanes via Nickel-Catalyzed Reductive Cross-Coupling
作者:Julie L. Hofstra、Alan H. Cherney、Ciara M. Ordner、Sarah E. Reisman
DOI:10.1021/jacs.7b11707
日期:2018.1.10
asymmetric Ni-catalyzed reductive cross-coupling has been developed to prepare enantioenriched allylic silanes. This enantioselective reductive alkenylation proceeds under mild conditions and exhibits good functional group tolerance. The chiral allylic silanes prepared here undergo a variety of stereospecific transformations, including intramolecular Hosomi-Sakurai reactions, to set vicinal stereogenic centers
已开发出不对称 Ni 催化的还原交叉偶联来制备对映体富集的烯丙基硅烷。这种对映选择性还原烯基化在温和条件下进行,并表现出良好的官能团耐受性。这里制备的手性烯丙基硅烷经过各种立体定向转化,包括分子内细美-樱井反应,以设置具有优异手性转移的邻位立体中心。
S<sub>N</sub>2″-Selective and Enantioselective Substitution with Unsaturated Organoboron Compounds and Catalyzed by a Sulfonate-Containing NHC-Cu Complex
作者:Yuebiao Zhou、Ying Shi、Sebastian Torker、Amir H. Hoveyda
DOI:10.1021/jacs.8b10885
日期:2018.12.5
53-89% yield, 69-96% SN2″ selectivity, 98:2 to >98:2 E: Z ratio, and 94:6-98:2 er. Insight regarding several of the unique mechanistic attributes of the catalytic process was obtained on the basis of kinetic isotope effect measurements and DFT studies. These investigations indicate that cationic π-allyl-Cu complexes are likely intermediates, clarifying the role of the s-cis and s-trans conformers of
Asymmetric Synthesis of Both Enantiomers of <i>a</i><i>nti</i>-4,4,4-Trifluorothreonine and 2-Amino-4,4,4-trifluorobutanoic Acid
作者:Zhong-Xing Jiang、Ying-Ying Qin、Feng-Ling Qing
DOI:10.1021/jo0344384
日期:2003.9.1
A short and efficient enantioselective synthesis of bothenantiomers of anti-4,4,4-trifluorothreonine and 2-amino-4,4,4-trifluorobutanoic acid was successfully developed. Trifluoromethylation of benzyl-protected bromoalkene 4 provided key intermediate trifluoromethylated trans-disubstituted alkene 2 in good yield. The sequence then involved Sharpless asymmetric dihydroxylation, nucleophilic opening