4139-78-0Relevant academic research and scientific papers
Halogen-Bridged Methylnaphthyl Palladium Dimers as Versatile Catalyst Precursors in Coupling Reactions
Doppiu, Angelino,Goo?en, Lukas J.,Hu, Zhiyong,Pirkl, Nico,Sivendran, Nardana
supporting information, p. 25151 - 25160 (2021/10/19)
Halogen-bridged methylnaphthyl (MeNAP) palladium dimers are presented as multipurpose Pd-precursors, ideally suited for catalytic method development and preparative organic synthesis. By simply mixing with phosphine or carbene ligands, they are in situ converted into well-defined monoligated complexes. Their catalytic performance was benchmarked against state-of-the-art systems in challenging Buchwald–Hartwig, Heck, Suzuki and Negishi couplings, and ketone arylations. Their use enabled record-setting activities, beyond those achievable by optimization of the ligand alone. The MeNAP catalysts permit syntheses of tetra-ortho-substituted arenes and bulky anilines in near-quantitative yields at room temperature, allow mono-arylations of small ketones, and enable so far elusive cross-couplings of secondary alkyl boronic acids with aryl chlorides.
Mesoionic N-heterocyclic olefin catalysed reductive functionalization of CO2for consecutiveN-methylation of amines
Das, Arpan,Maji, Subir,Mandal, Swadhin K.
, p. 12174 - 12180 (2021/09/28)
A mesoionic N-heterocyclic olefin (mNHO) was introduced as a metal-free catalyst for the reductive functionalization of CO2leading to consecutive doubleN-methylation of primary amines in the presence of 9-borabicyclo[3.3.1]nonane (9-BBN). A wide range of secondary amines and primary amines were successfully methylated under mild conditions. The catalyst sustained over six successive cycles ofN-methylation of secondary amines without compromising its activity, which encouraged us to check its efficacy towards doubleN-methylation of primary amines. Moreover, this method was utilized for the synthesis of two commercially available drug molecules. A detailed mechanistic cycle was proposed by performing a series of control reactions along with the successful characterisation of active catalytic intermediates either by single-crystal X-ray study or by NMR spectroscopic studies in association with DFT calculations.
Iridium-Catalyzed Highly Efficient and Site-Selective Deoxygenation of Alcohols
Yang, Shiyi,Tang, Weiping,Yang, Zhanhui,Xu, Jiaxi
, p. 9320 - 9326 (2018/09/21)
An iridium-catalyzed, highly efficient, and site-selective deoxygenation of primary, secondary, and tertiary alcohols has been realized, under the assistance of a 4-(N-substituted amino)aryl directing group. Only the hydroxyl adjacent to the directing group can be deoxygenated. The deoxygenation is performed in water, with formic acid as both the promoter and hydride donor. Excellent yields and functionality tolerance, as well as high efficiency (S/C up to 1000 000, TOF up to 445 000 h-1), are obtained. The kinetic isotope effect studies show that hydride formation is the rate-determining step, and the deoxygenation follows an SN1-type pathway. The deoxygenation protocol has been demonstrated useful in the structural modification of naturally occurring ketones and steroids.
Pd-Catalyzed Alkylation of (Iso)quinolines and Arenes: 2-Acylpyridine Compounds as Alkylation Reagents
Wu, Qingsong,Han, Shuaijun,Ren, Xiaoxiao,Lu, Hongtao,Li, Jingya,Zou, Dapeng,Wu, Yangjie,Wu, Yusheng
supporting information, p. 6345 - 6348 (2018/10/20)
The first Pd-catalyzed alkylation of (iso)quinolines and arenes is reported. The readily available and bench-stable 2-acylpyridine compounds were used as an alkylation reagent to form the structurally versatile alkylated (iso)quinolines and arenes. The method affords a convenient pathway for the introduction of alkyl groups into organic molecules.
Base-oxidant promoted metal-free N-demethylation of arylamines
Botla, Vinayak,Barreddi, Chiranjeevi,Daggupati, Ramana V,Malapaka, Chandrasekharam
, p. 1469 - 1473 (2016/09/19)
A metal-free oxidative N-demethylation of arylamines with triethylamine as a base and tert-butyl hydroperoxide (TBHP) as oxidant is reported in this paper. The reaction is general, practical, inexpensive, non-toxic, and the method followed is environmentally benign, with moderate to good yields. [Figure not available: see fulltext.]
Iron(III)-catalyzed C-H functionalization: Ortho-benzoyloxylation of N,N-dialkylanilines and its application to 1,4-benzoxazepines
Chiranjeevi, Barreddi,Vinayak, Botla,Parsharamulu, Thupakula,PhaniBabu, Vemulapalli S.,Jagadeesh, Bharatam,Sridhar, Balasubramanian,Chandrasekharam, Malapaka
, p. 7839 - 7849 (2015/01/16)
A C-O bond-formation reaction that proceeds through C-H functionalization of N,N-dialkylanilines at the ortho-position is presented. The iron-catalyzed selective ortho-benzoyloxylation follows a polar Friedel-Crafts-like mechanism and is sensitive to the nucleophilicity of the anilines. The benzoyl-oxylation of a variety of N,N-disubstituted anilines and Nphenyl heterocycles is carried out under extremely mild conditions. Furthermore, the methodology has been successfully employed for the generation of 1,4-benzoxazepines and oaminophenols.
Palladium-catalysed direct cross-coupling of secondary alkyllithium reagents
Vila, Carlos,Giannerini, Massimo,Hornillos, Valentin,Fananas-Mastral, Martin,Feringa, Ben L.
, p. 1361 - 1367 (2014/03/21)
Palladium-catalysed cross-coupling of secondary C(sp3) organometallic reagents has been a long-standing challenge in organic synthesis, due to the problems associated with undesired isomerisation or the formation of reduction products. Based on our recently developed catalytic C-C bond formation with organolithium reagents, herein we present a Pd-catalysed cross-coupling of secondary alkyllithium reagents with aryl and alkenyl bromides. The reaction proceeds at room temperature and on short timescales with high selectivity and yields. This methodology is also applicable to hindered aryl bromides, which are a major challenge in the field of metal catalysed cross-coupling reactions.
Iron-catalyzed aryl-aryl cross coupling route for the synthesis of 1-(2-amino)-phenyl)dibenzo[b,d]furan-2-ol derivatives and their biological evaluation
Chiranjeevi, Barreddi,Koyyada, Ganesh,Prabusreenivasan,Kumar, Vanaja,Sujitha, Pombala,Kumar, C. Ganesh,Sridhar,Shaik, Saida,Chandrasekharam, Malapaka
, p. 16475 - 16485 (2013/09/23)
Naturally occurring dibenzofuran motifs represent promising lead structures for the development of novel antimycobacterial agents. Prompted by our recent development of cross dehydrogenative coupling using iron catalysis, we extended our strategy to synthesize 14 novel anilinodibenzofuranols and they were explored for anti-tubercular and cytotoxic activities. Consistent with our hypothesis, DBF-3, 14 and 16 exhibited promising activity against two strains (M. tuberculosis H37Rv and the clinical S, H, R, and E resistant isolate), while DBF-13, 18 exhibited selective inhibitory activity only against the clinical S, H, R and E resistant isolate. However, the compounds DBF-4 and DBF-8 showed promising and selective antitumor activity against the tested cancer cell lines. The Royal Society of Chemistry 2013.
Direct catalytic cross-coupling of organolithium compounds
Giannerini, Massimo,Fananas-Mastral, Martin,Feringa, Ben L.
, p. 667 - 672 (2013/08/23)
Catalytic carbon-carbon bond formation based on cross-coupling reactions plays a central role in the production of natural products, pharmaceuticals, agrochemicals and organic materials. Coupling reactions of a variety of organometallic reagents and organic halides have changed the face of modern synthetic chemistry. However, the high reactivity and poor selectivity of common organolithium reagents have largely prohibited their use as a viable partner in direct catalytic cross-coupling. Here we report that in the presence of a Pd-phosphine catalyst, a wide range of alkyl-, aryl- and heteroaryl-lithium reagents undergo selective cross-coupling with aryl- and alkenyl-bromides. The process proceeds quickly under mild conditions (room temperature) and avoids the notorious lithium halogen exchange and homocoupling. The preparation of key alkyl-, aryl- and heterobiaryl intermediates reported here highlights the potential of these cross-coupling reactions for medicinal chemistry and material science.
