Gold-catalyzed Cycloisomerization of 2-Aryl-2-(arylamino)-3-butyn-1-ols toward 2-(2′-Aminoaryl)-2,5-dihydrofurans
摘要:
AbstractAn interesting and highly selective gold‐catalyzed cycloisomerization of 2‐aryl‐2‐(arylamino)‐3‐butyn‐1‐ols to afford 2‐(2′‐aminoaryl)‐2,5‐dihydrofurans has been reported. The reaction is atom economic and highly efficient, and tolerates many functional groups including the cyano and allyl groups. A plausible mechanism for this new cycloismerization is also proposed.magnified image
Borylation of Propargylic Substrates by Bimetallic Catalysis. Synthesis of Allenyl, Propargylic, and Butadienyl Bpin Derivatives
摘要:
Bimetallic Pd/Cu and Pd/Ag catalytic systems were used for borylation of propargylic alcohol derivatives. The substrate scope includes even terminal alkynes. The reactions proceed stererospecifically with formal S(N)2' pathways to give allenyl boronates. Opening of propargyl epoxides leads to 1,2-diborylated butadienes probably via en allenylboronate intermediate.
Sodium Iodide/<i>tert</i>-Butyl(dimethyl)silyl Chloride-Induced Isomerization of 2,3-Allenols to 2(<i>E</i>)-Enals
作者:Rong Zeng、Zhichao Ma、Chunling Fu、Shengming Ma
DOI:10.1002/adsc.201300835
日期:2014.4.14
Through an unexpected CC bond migration, 2(E)‐enals were efficiently prepared highly stereoselectively in moderate to good yields via the sodiumiodide/tert‐butyl(dimethyl)silyl chloride (NaI/TBSCl)‐mediated reaction of the easily available 2,3‐allenols. Based on a careful mechanistic study, including control experiments and deuterium‐labeling experiments, an electron‐withdrawing substituent group