Substituent-Guided Switch between CH Activation and Decarboxylative Cross-Coupling during Palladium/Copper-Catalyzed Cascade Reactions of 2-Aminobenzoates with 2-Haloarylaldehydes
作者:Subhendu Bhowmik、Garima Pandey、Sanjay Batra
DOI:10.1002/chem.201301705
日期:2013.8.5
Phenanthridines, pyrazole[4,3‐c]quinolines and isocryptolepine were prepared in one step from the Pd/Cu‐catalyzed reaction between potassium 2‐aminobenzoates and 2‐haloarylaldehydes (see scheme). Although the reactions of 2‐aminobenzoates proceeded via a cascade imination/CH functionalization, the reactions of 6‐nitro‐2‐aminobenzoates ensued via a tandem imination/decarboxylative cross‐coupling.
级联转换:由2-氨基苯甲酸钾和2-卤代芳基醛之间的Pd / Cu催化反应一步制得菲啶,吡唑[4,3- c ]喹啉和异隐油菜碱(参见方案)。虽然经由级联亚胺化/ C进行2-氨基苯甲酸酯反应 ħ官能化,6-硝基-2-氨基苯甲酸酯的反应中通过串联亚胺化/脱羧交叉偶联接踵而至。
An efficient metal-free and catalyst-free C–S/C–O bond-formation strategy: synthesis of pyrazole-conjugated thioamides and amides
作者:Shubham Sharma、Dharmender Singh、Sunit Kumar、Vaishali、Rahul Jamra、Naveen Banyal、Deepika、Chandi C Malakar、Virender Singh
DOI:10.3762/bjoc.19.22
日期:——
described for the synthesis of pyrazole-tethered thioamide and amide conjugates. The thioamides were generated by employing a three-componentreaction of diverse pyrazole C-3/4/5 carbaldehydes, secondary amines, and elemental sulfur in a single synthetic operation. The advantages of this developed protocol refer to the broad substrate scope, metal-free and easy to perform reaction conditions. Moreover
Abstract The diastereoselective synthesis of novel pyrazole and dihydrofuranone-based molecular hybrids has been unfolded through the development of a straightforward tandem strategy. The indium-mediated Barbier-typeallylation reaction was followed by an in situ lactonization approach. No additives were required for this transformation, and high yields of dihydrofuranone derivatives were obtained
Straightforward copper-catalyzed synthesis of pyrrolopyrazoles from halogenated pyrazolecarbaldehydes
作者:Maloy Nayak、Harikrishna Batchu、Sanjay Batra
DOI:10.1016/j.tetlet.2012.05.148
日期:2012.8
Straightforward synthesis of a variety of pyrrolo-fused pyrazoles via a cascade reaction between halopyrazolecarbaldehydes and ethylisocyanoacetate in the presence of copper and a base is described. (C) 2012 Elsevier Ltd. All rights reserved.