established that a cyclopentadienyl RhIII complex with two phenyl groups and a pendant amide moiety catalyzes the formal Lossen rearrangement/[3+2] annulation cascade of N‐pivaloyl benzamides and acrylamides with alkynes leading to substituted indoles and pyrroles. Mechanistic studies revealed that this cascade reaction proceeds via not the Lossen rearrangement to form anilides or enamides but C−H bond cleavage
The CH Activation/1,3-Diyne Strategy: Highly Selective Direct Synthesis of Diverse Bisheterocycles by Rh<sup>III</sup>Catalysis
作者:Da-Gang Yu、Francisco de Azambuja、Tobias Gensch、Constantin G. Daniliuc、Frank Glorius
DOI:10.1002/anie.201403782
日期:2014.9.1
The reactivity and selectivity of 1,3‐diynes in transition‐metal‐catalyzed CH activation is exploited to quickly assemble diverse polysubstituted bisheterocycles, which are highly important but difficult to access. By using the CH activation/1,3‐diyne strategy, we overcame the challenges of selectivity (chemo‐, regio‐, and mono‐/diannulation) and constructed seven kinds of adjacent bisheterocycles
Rhodium(III)-Catalyzed C–H Activation: Ligand-Controlled Regioselective Synthesis of 4-Methyl-Substituted Dihydroisoquinolones
作者:Joyann S. Barber、Stephanie Scales、Michelle Tran-Dubé、Fen Wang、Neal W. Sach、Louise Bernier、Michael R. Collins、JinJiang Zhu、Indrawan J. McAlpine、Ryan L. Patman
DOI:10.1021/acs.orglett.9b02029
日期:2019.7.19
Rh-catalyzed C–H functionalization of O-pivaloyl benzhydroxamic acids with propene gas provides access to 4-methyl-substituted dihydroisoquinolones. Good to excellent levels of regioselectivity are achieved using [CptRhCl2]2 as a precatalyst under optimized conditions. Thorough examination of aryl/heteroaryl O-pivaloyl hydroxamic acid substrates, ligand effects on C–Hsiteselectivity, alkene scope
Rh催化O-新戊酰基苯氧肟酸的C–H官能团与丙烯气体的接触提供了被4-甲基取代的二氢异喹诺酮类化合物的途径。在优化的条件下,使用[Cp t RhCl 2 ] 2作为预催化剂,可以实现良好至优异的区域选择性。全面讨论了芳基/杂芳基O-新戊基异羟肟酸底物的检测,配体对C–H位置选择性,烯烃范围和规模证明的影响。
Regioselective Synthesis of 5-Aminooxazoles via Cp*Co(III)-Catalyzed Formal [3 + 2] Cycloaddition of <i>N</i>-(Pivaloyloxy)amides with Ynamides
作者:Xiang-Lei Han、Chu-Jun Zhou、Xu-Ge Liu、Shang-Shi Zhang、Honggen Wang、Qingjiang Li
DOI:10.1021/acs.orglett.7b02959
日期:2017.11.17
efficient protocol for the regioselective synthesis of 5-aminooxazoles is disclosed. The reaction, catalyzed by a cheap Cp*Co(III) catalyst, starts from easily accessible N-(pivaloyloxy)amides and ynamides. Mild reaction conditions, a broad substrate scope, good functional group tolerance, and good to excellent yields were observed.
Asymmetric Synthesis of Isoindolones by Chiral Cyclopentadienyl-Rhodium(III)-Catalyzed CH Functionalizations
作者:Baihua Ye、Nicolai Cramer
DOI:10.1002/anie.201404895
日期:2014.7.21
Directed Cp*RhIII‐catalyzed carbon–hydrogen (CH) bond functionalizations have evolved as a powerful strategy for the construction of heterocycles. Despite their high value, the development of related asymmetric reactions is largely lagging behind due to a limited availability of robust and tunable chiral cyclopentadienyl ligands. Rhodium complexes comprising a chiral Cp ligand with an atropchiral