02016nas a2200193   4500008004100000245014400041210006900185260000800254300001400262490000700276520128500283100002401568700002201592700002301614700002401637700001701661700002001678856012401698       2016                        eng d00aMechanistic insights into pincer-ligated palladium-catalyzed arylation of azoles with aryl Iodides: evidence of a Pd-II-Pd-IV-Pd-II pathway0 aMechanistic insights into pincerligated palladiumcatalyzed aryla  cMAR  a875–8860 v353 a<p>Pincer-based (R2POCNR′2)PdCl complexes along with CuI cocatalyst catalyze the arylation of azoles with aryl iodides to give the 2-arylated azole products. Herein, we report an extensive mechanistic investigation for the direct arylation of azoles involving a well-defined and highly efficient (iPr2POCNEt2)PdCl (2a) catalyst, which emphasizes a rare PdII–PdIV–PdII redox catalytic pathway. Kinetic studies and deuterium labeling experiments indicate that the C–H bond cleavage on azoles occurs via two distinct routes in a reversible manner. Controlled reactivity of the catalyst 2a underlines the iodo derivative (iPr2POCNEt2)PdI (3a) to be the resting state of the catalyst. The intermediate species (iPr2POCNEt2)Pd-benzothiazolyl (4a) has been isolated and structurally characterized. A determination of reaction rates of compound 4a with electronically different aryl iodides has revealed the kinetic significance of the oxidative addition of the C(sp2)–X electrophile, aryl iodide, to complex 4a. Furthermore, the reactivity behavior of 4a suggests that the arylation of benzothiazole proceeds via an oxidative addition/reductive elimination pathway involving a (iPr2POCNEt2)PdIV(benzothiazolyl)(Ar)I species, which is strongly supported by DFT calculations.</p>1 aKhake, Shrikant, M.1 aJagtap, Rahul, A.1 aDangat, Yuvraj, B.1 aGonnade, Rajesh, G.1 aVanka, Kumar1 aPunji, Benudhar  uhttp://library.ncl.res.in/content/mechanistic-insights-pincer-ligated-palladium-catalyzed-arylation-azoles-aryl-iodides01202nas a2200169   4500008004100000022001400041245009000055210006900145260000800214300001400222490000700236520060400243100002200847700002400869700002000893856011900913       2020                        eng d  a1523-706000aMnBr2-catalyzed direct and site-selective alkylation of indoles and benzo[h]quinoline0 aMnBr2catalyzed direct and siteselective alkylation of indoles an  cJUN  a4643-46470 v223 a<p>Manganese-catalyzed regioselective C-H alkylation of indoles and benzo[h]quinoline with a variety of unactivated alkyl iodides is reported. Unlike other Mn-catalyzed C-H functionalization, this protocol does not require a Grignard reagent base and employs a simple and inexpensive MnBr2 as a catalyst. This method tolerates diverse functionalities, including fluoro, chloro, bromo, iodo, alkenyl, alkynyl, pyrrolyl, and carbazolyl groups. The alkylation proceeds through a single-electron transfer pathway comprising reversible C-H manganesation and involving an alkyl radical intermediate.</p>
1 aJagtap, Rahul, A.1 aVerma, Suryadev, K.1 aPunji, Benudhar  uhttp://library.ncl.res.in/content/mnbr2-catalyzed-direct-and-site-selective-alkylation-indoles-and-benzohquinoline