Palladium-Catalyzed Cross-Coupling Reaction of Bis(pinacolato)diboron with 1-Alkenyl Halides or Triflates: Convenient Synthesis of Unsymmetrical 1,3-Dienes via the Borylation-Coupling Sequence
1-alkenylboronic acid pinacol esters via a palladium-catalyzed cross-coupling reaction of bis(pinacolato)diboron (pin(2)B(2), pin = Me(4)C(2)O(2)) with 1-alkenyl halides or triflates was carried out in toluene at 50 degrees C in the presence of KOPh (1.5 equiv) and PdCl(2)(PPh(3))(2)-2Ph(3)P (3 mol %). The borylation of acyclic and cyclic 1-alkenyl bromides and triflates was achieved in high yields with complete
Synthesis of 1-Alkenylboronic Esters<i>via</i>Palladium-Catalyzed Cross-Coupling Reaction of Bis(pinacolato)diboron with 1-Alkenyl Halides and Triflates
The synthesis of 1-alkenylboronic acid pinacol esters via the palladium-catalyzed cross-coupling reaction of 1-alkenyl halides or triflates with bis(pinacolato)diboron [(Me4C2O2)B-B(O2C2 Me4)] was carried out in toluene at 50 °C in the presence of potassium phenoxide (1.5 equivalents) and PdCl2(PPh3)2·2PPh3 (3 mol%).
A novel and efficient route to azabicycles via the isocyanate-mediated twofold cyclization
作者:Mingming Li、Ping Xing、Biao Jiang
DOI:10.1016/j.tet.2016.01.050
日期:2016.3
A new one-pot route to azabicycles involving the [3,3]-sigmatropicrearrangement of dehydration product from allylic alcohol carbamate and base promoted twofold cyclization was described.
Bifunctional Phosphine-Enabled Regioselective Cycloisomerization of Enynyl Esters En Route to Bicyclo[2.2.1]heptenes
作者:Philip Kohnke、Liming Zhang
DOI:10.1021/acs.orglett.3c00161
日期:2023.3.3
esters and the Diels–Alder reaction. The gold catalysis permits the use of enynyl substrates without additional propargylic substitution and achieves the highly regioselective formation of less stable cyclopentadienyl esters. The regioselectivity is enabled by a bifunctional phosphine ligand, the remote aniline group of which facilitates α-deprotonation of a gold carbene intermediate. The reaction works
Development of a Protocol for Eight- and Nine-Membered Ring Synthesis in the Annulation of sp<sup>2</sup>,sp<sup>3</sup>-Hybridized Organic Dihalides with Keto Esters
作者:Gary A. Molander、Christoph Köllner
DOI:10.1021/jo001195w
日期:2000.12.1
eight- and nine-membered carbocycles. In this process wherein one alkenyl- or arylbromide and a tethered alkyl chloride comprise the organic dihalide, a selective metal-halogen exchange reaction between the sp(2)-hybridized bromide and an organolithium initiates the process. Transmetalation to an organoytterbium reagent generates a species that undergoes selective carbonyl addition to the ketone of