A mild and efficient protocol for the synthesis of 2,2′-difunctional biaryls from readily available benzamides and oximes by Co(OAc)2·4H2O catalysis has been developed. The catalytic cycle that includes aerobic oxidation of Co(I) to Co(III) is successfully achieved for the first time through dual-chelation-assisted C–H/C–H coupling with the assistance of catalytic Mn(acac)3. The catalytic system exhibits
Preparation of 2‐(1<i>H</i>‐pyrazol‐5‐yl)benzenesulfonamides from polylithiated C(α),N‐carbo‐<i>tert</i>‐butoxyhydrazones and methyl 2‐(aminosulfonyl)benzoate
作者:John D. Knight、Jordan B. Brown、Jason S. Overby、Charles F. Beam、N. Dwight Camper
DOI:10.1002/jhet.5570450122
日期:2008.1
Select C(α), N-carbo-tert-butoxyhydrazones were dilithiated with excess lithium diisopropylamide followed by condensation with methyl 2-(aminosulfonyl)benzoate, acid cyclization, hydrolysis, and decarboxylation to afford new 2-(1H-pyrazol-5-yl)benzenesulfonamides, [NH-pyrazolyl-ortho-benzene-sulfonamides].
<b>Hydrohydrazination of Arylalkynes Catalyzed by an Expanded Ring N-Heterocyclic Carbene (er-NHC) Gold Complex Under Solvent-Free Conditions</b>
作者:Oleg S. Morozov、Pavel S. Gribanov、Andrey F. Asachenko、Pavel V. Dorovatovskii、Victor N. Khrustalev、Viktor B. Rybakov、Mikhail S. Nechaev
DOI:10.1002/adsc.201500658
日期:2016.4.28
electron donating, sterically bulky THD‐Dipp (1,3‐bis(2,6‐diisopropylphenyl)hexahydro‐2H‐1,3‐diazepine‐2‐ylidene) seven‐membered N‐heterocyclic carbene ligand, efficiently promotes intermolecular addition of Ts‐ and Boc‐hydrazine to arylalkynes undersolvent‐freeconditions.
[(THD-Dipp)AuOTf],受强电子给体,空间庞大的THD-Dipp(1,3-二(2,6-二异丙基苯基)六氢-2 H -1,3-二氮杂-2-亚基)的支持7 N元杂环卡宾配体可在无溶剂条件下有效促进Ts和Boc肼分子间加成至芳炔基。
I<sub>2</sub>–TBHP-Catalyzed Oxidative Cross-Coupling of <i>N</i>-Sulfonyl Hydrazones and Isocyanides to 5-Aminopyrazoles
作者:Gopal Chandru Senadi、Wan-Ping Hu、Ting-Yi Lu、Amol Milind Garkhedkar、Jaya Kishore Vandavasi、Jeh-Jeng Wang
DOI:10.1021/acs.orglett.5b00398
日期:2015.3.20
I-2-TBHP-catalyzed oxidative cross coupling of N-sulfonyl hydrazones with isocyanides has been realized for the synthesis of 5-aminopyrazoles through formal [4 + 1] annulation via in situ azoalkene formation. Notable features are the metal/alkyne-free strategy, C-C and C-N bond formation, atom economy, catalytic I-2, broad functional group tolerance, good reaction yields, shorter time, and also applicability to one-pot methodology.
Iridium-catalyzed selective N-allylation of hydrazines
作者:Robert Matunas、Amy J. Lai、Chulbom Lee
DOI:10.1016/j.tet.2005.03.105
日期:2005.6
A highly chemo- and regioselective iridium-catalyzed allylic amination is described. The reaction of various hydrazones and hydrazides with allylic carbonates proceeds at ambient temperature in the presence of an [Ir(COD)Cl](2)/pyridine catalyst, ammonium iodide. and diethylzinc to afford the corresponding N-allylation products in high yields with excellent chemo- and regioselectivities. Only the more nucleophilic nitrogen of a given hydrazine, derivative undergoes the C-N bond formation to yield a branched allylic isomer as the exclusive product. (c) 2005 Elsevier Ltd. All rights reserved.