Rh(III)-Catalyzed Synthesis of <i>N</i>-Unprotected Indoles from Imidamides and Diazo Ketoesters via C–H Activation and C–C/C–N Bond Cleavage
作者:Zisong Qi、Songjie Yu、Xingwei Li
DOI:10.1021/acs.orglett.5b03669
日期:2016.2.19
The synthesis of N-unprotected indoles has been realized via Rh(III)-catalyzed C–Hactivation/annulation of imidamides with α-diazo β-ketoesters. The reaction occurs with the release of an amide coproduct, which originates from both the imidamide and the diazo as a result of C═N cleavage of the imidamide and C–C(acyl) cleavage of the diazo. A rhodacyclic intermediate has been isolated and a plausible
Copper-catalyzed synthesis of 2,3-disubstituted indoles from ortho-haloanilines and β-keto esters/β-diketone
作者:Xiao-Guang Liu、Zi-Hao Li、Jian-Wei Xie、Ping Liu、Jie Zhang、Bin Dai
DOI:10.1016/j.tet.2015.12.006
日期:2016.2
Tetrazole-1-acetic acid was identified as an efficient ligand to promote copper-catalyzed domino reaction of ortho-iodo/bromo-anilines with β-keto esters/β-diketone for 2,3-disubstitutedindoles' synthesis with high yields undermildconditions. The protocol, with easy-available catalytic system, shows good substrate tolerance towards various functional groups.
Reactions of 2-iodoanilines with ethyl buta-2,3-dienoate catalyzed by potassium carbonate and CuI in one pot generate the corresponding ethyl 2-methyl-1H-indole-3-carboxylate products in moderate yields under mild conditions. indoles - aniline - allenes - copper - catalysis
Ruthenium(II)‐Catalyzed C−H Activation of Imidamides and Divergent Couplings with Diazo Compounds: Substrate‐Controlled Synthesis of Indoles and 3
<i>H</i>
‐Indoles
作者:Yunyun Li、Zisong Qi、He Wang、Xifa Yang、Xingwei Li
DOI:10.1002/anie.201606316
日期:2016.9.19
Indoles are an important structural motif that is commonly found in biologically active molecules. In this work, conditions for divergentcouplings between imidamides and acceptor–acceptor diazo compounds were developed that afforded NH indoles and 3H‐indoles under ruthenium catalysis. The coupling of α‐diazoketoesters afforded NH indoles by cleavage of the C(N2)−C(acyl) bond whereas α‐diazomalonates
dearomative reductive Heck reaction of N-(o-bromoaryl) indole-3-carboxamide is developed. By employing Pd(dba)2/SPINOL-based phosphoramidite as the chiral catalyst and HCO2Na as the hydride source, a series of enantioenriched spiro indolines bearing vicinal stereocenters were afforded in moderate to good yields with excellent enantioselectivities. The reductive Heck reaction of formal tetrasubstituted