A practical and effective copper-catalyzed dehydrogenative Diels–Alderreaction of gem-diesters and ketone with dienes has been established. The active dienophiles were generated in situ via a radical-based dehydrogenation process, which reacted with a wide variety of dienes to afford various polysubstituted cyclohexene derivatives in good to excellent yields.
Palladium‐Catalyzed Tail‐to‐Tail Reductive Dimerization of Terminal Alkynes to 2,3‐Dibranched Butadienes
作者:Hongyu Guo、Sheng Zhang、Yang Li、Xiaoqiang Yu、Xiujuan Feng、Yoshinori Yamamoto、Ming Bao
DOI:10.1002/anie.202116870
日期:2022.3.21
a combination of pivalic acid and para-toluenesulfonic acid proved successful in favoring the selective highly chemo- and regioselective tail-to-tail reductive dimerization of terminalalkynes over the competitive head-to-taildimerization pathway. The target reaction, proposed to proceed via a cationic alkenyl palladium intermediate, presents a facile and straightforward approach for accessing 2,3-dibranched
It is shown that industrially available 2,3-dichloro-1,3-butadiene is a useful starting material for the synthesis of 2,3-diaryl-1,3-butadienes. Ni(II)-catalyzed cross-coupling reaction of 2,3-dichloro-1,3-butadiene with ArMgBr (Ar = 2-thienyl, phenyl, 4-dodecyloxyphenyl, and 4-fluorophenyl) gives the corresponding 2,3-diaryl-1,3-butadienes in good yields.
Quinonediimines as redox-active organocatalysts for oxidative coupling of aryl- and alkenylmagnesium compounds under molecular oxygen
作者:Toru Amaya、Riyo Suzuki、Toshikazu Hirao
DOI:10.1039/c6cc03053j
日期:——
N,N′-Diphenyl-p-benzoquinonediimine worked as a redox-active organocatalyst for the oxidative homo-coupling of aryl- and alkenylmagnesium compounds under molecular oxygen.