A convenient hydroiodination of alkynes using I2/PPh3/H2O and its application to the one-pot synthesis of trisubstituted alkenes via iodoalkenes using Pd-catalyzed cross-coupling reactions
作者:Shin-ichi Kawaguchi、Yuhei Gonda、Haruna Masuno、Huệ Thị Vũ、Kotaro Yamaguchi、Hiroyuki Shinohara、Motohiro Sonoda、Akiya Ogawa
DOI:10.1016/j.tetlet.2014.10.039
日期:2014.12
A facile hydroiodination of alkynes using readily-available reagents such as I2, PPh3, and H2O has been developed. This is extended to the one-pot synthesis of trisubstituted alkenes from alkynes via iodoalkenes using Pd-catalyzed cross-coupling and related methods such as the Suzuki–Miyaura cross-coupling, Sonogashira cross-coupling reaction, and Mizoroki–Heck reaction.
Aryl- and alkenylsilanediols, which possess two hydroxy groups on the silicon atom, undergo the rhodium-catalyzed addition of an organic group on silicon to internal alkynes. Treatment of several internal alkynes with aryl- or alkenylsilanediols in the presence of 3 mol% of [Rh(OH)(cod)]2 affords the hydroarylated or hydroalkenylated products in good yields. A crucial role of the hydroxy group of silanediol for the catalytic reaction is also discussed with the related aryltin reagent.
The title reaction was found to proceed in the presence of a rhodium/1,2-bis(diphenylphosphino)benzene catalyst. Variously substituted arylethenes and 1,3-dienes were obtained in good yields.
Highly Selective and Practical Alkyne-Alkyne Cross-Coupling Using Cp2ZrBu2 and Ethylene
作者:Zhenfeng Xi、Ryuichiro Hara、Tamotsu Takahashi
DOI:10.1021/jo00119a022
日期:1995.7
Highly selective alkyne-alkyne cross coupling reactions were achieved using Cp(2)ZrBu(2) and ethylene gas. First, alkynes were treated with 1.2 equiv of Cp(2)ZrBu(2) (Negishi reagent) under ethylene gas to give zirconacyclopentenes with high selectivities. Subsequent addition of a second alkyne to the solution of zirconacyclopentenes at 50 degrees C gave unsymmetrical zirconacyclopentadienes selectively. After hydrolysis unsymmetrical dienes were obtained in high yields.