Remote ether groups-directed regioselective and chemoselective cycloaddition of azides and alkynes
作者:Xuelun Duan、Nan Zheng、Ming Li、Xinhao Sun、Zhuye Lin、Pan Qiu、Wangze Song
DOI:10.1016/j.cclet.2021.05.037
日期:2021.12
5-regioselectivities and excellent chemoselectivities. Ether group could coordinate with iridium catalyst by lone-pair electron at a distance (up to four σ bonds) away from alkyne to control the regioselectivity by weak coordination effect. The cycloaddition reaction chemoselectively occurred at the propargyl ether moiety of diyne to give unique fully substituted 4-alkynyl-triazole.
Rhodium‐Catalyzed Atroposelective Construction of Indoles via C−H Bond Activation
作者:Lincong Sun、Haohua Chen、Bingxian Liu、Junbiao Chang、Lingheng Kong、Fen Wang、Yu Lan、Xingwei Li
DOI:10.1002/anie.202012932
日期:2021.4.6
rhodium(III)‐catalyzed C−H activation of anilines bearing an N‐isoquinolyl directing group for oxidative [3+2] annulation with four classes of internal alkynes, leading to atroposelective indolesynthesis via dynamic kinetic annulation with C‐N reductive elimination constituting the stereo‐determining step. This reaction proceeds under mild conditions with high regio‐ and enantioselectivity and functional
Hydrophosphination of Propargylic Ethers with Diphenylphosphine in the Presence of LiHMDS,<i>N</i>-Heterocyclic Carbene, and Ti(NMe<sub>2</sub>)<sub>4</sub>
Regio- and stereoselective hydrophosphination of propargylic ethers with diphenylphosphine has been achieved using three-component catalyst, LiN(SiMe3)2/1,3-dimethylimidazol-2-ylidene/Ti(NMe2)4 (10 mol % of each).
Cp<sub>2</sub>TiCl<sub>2</sub>-catalyzed hydrocarboxylation of alkynes with CO<sub>2</sub>: formation of α,β-unsaturated carboxylic acids
作者:Peng Shao、Sheng Wang、Gaixia Du、Chanjuan Xi
DOI:10.1039/c6ra25003c
日期:——
Cp2TiCl2-catalyzed hydrocarboxylation of alkynes with CO2 (atmospheric pressure) has been reported. A range of alkynes were transformed to the corresponding α,β-unsaturatedcarboxylicacids in high yields with high regioselectivity. The reaction proceeded with hydrotitanation, transmetalation, and subsequently carboxylation with CO2.
Copper‐Catalyzed Synthesis of Tetrasubstituted Alkenes via Regio‐ and
<i>anti</i>
‐Selective Addition of Silylboronates to Internal Alkynes
作者:Hirokazu Moniwa、Ryo Shintani
DOI:10.1002/chem.202100933
日期:2021.5.12
As a new and complementary method for the synthesis of structurally defined tetrasubstituted alkenes, a copper‐catalyzed regio‐ and anti‐selectiveaddition of silylboronates to unsymmetric internal alkynes has been developed. A variety of unactivated alkynes can be employed with high selectivity under simple and mild conditions, and the resulting products have been further functionalized by utilizing