01525nas a2200241 4500008004100000022001400041245011600055210006900171260000900240300001400249490000800263520072100271653001400992653001901006653002501025653001101050653001101061653001701072100002201089700002301111700002001134856012901154 2020 eng d a1615-415000aCopper-catalyzed direct arylation of indoles and related (hetero)arenes: a ligandless and solvent-free approach0 aCoppercatalyzed direct arylation of indoles and related heteroar cJUN  a2534-25400 v3623 a

A ligandless and solvent-free copper-catalyzed method for the regioselective C-H bond arylation of indoles and related heteroarenes is reported. The use of CuCl efficiently catalyzes the direct coupling of diverse heteroarenes with aryl iodides via chelation-assistance. This reaction could tolerate sensitive and structurally diverse functionalities, including halides, ethers, thioethers, amines, indolyl, pyrrolyl and carbazolyl groups. The directing group, 2-pyridinyl can be smoothly removed to generate C-2 arylated free-NH indoles, and the arylated indoles can further be functionalized into Tryptamine derivatives. Preliminary mechanistic study revealed a radical pathway for the arylation reaction.

10aArylation10aC-H activation10aChelation-assistance10aCopper10aIndole10aSolvent-free1 aPandey, Dilip, K.1 aShabade, Anand, B.1 aPunji, Benudhar uhttps://library.ncl.res.in/content/copper-catalyzed-direct-arylation-indoles-and-related-heteroarenes-ligandless-and-solvent01576nas a2200229 4500008004100000022001400041245011100055210006900166260000800235300001400243490000800257520078000265653002001045653002401065653001201089653001901101653003501120100001901155700002301174700002001197856012901217 2021 eng d a1615-415000aAdvances in C(sp(2))-H/C(sp(2))-H oxidative coupling of (Hetero)arenes using 3d transition metal catalysts0 aAdvances in Csp2HCsp2H oxidative coupling of Heteroarenes using  cAPR a1998-20220 v3633 a

C-H/C-H oxidative coupling has emerged as a straightforward and powerful technique for the construction of (hetero)biaryls, with substantial application to drug discovery, agrochemicals, biology, and material sciences. Mainly aryl-aryl, aryl-heteroaryl, and heteroaryl-heteroaryl couplings via double C(sp(2))-H activation using 4d or 5d noble transition metal catalysts have been extensively studied. Considering the earth-abundant and inexpensive nature of 3d transition metals, the sustainable development of C(sp(2))-H/C(sp(2))-H oxidative coupling employing such metal catalysts has gained significant attention. In this review, we present a comprehensive overview of C(sp(2))-H/C(sp(2))-H oxidative coupling of (hetero)arenes catalyzed by 3d transition metals.

10a(hetero)biaryls10a3d transition metal10aBiaryls10aC-H activation10across-dehydrogenative coupling1 aBansal, Sadhna1 aShabade, Anand, B.1 aPunji, Benudhar uhttps://library.ncl.res.in/content/advances-csp2-hcsp2-h-oxidative-coupling-heteroarenes-using-3d-transition-metal-catalysts01604nas a2200241 4500008004100000022001400041245008000055210006900135260000900204300001400213490000700227520082200234653001901056653001501075653001901090653002201109653003001131100002801161700002301189700001801212700002001230856011201250 2021 eng d a2155-543500aUnactivated alkyl halides in transition-metal-catalyzed C-H bond alkylation0 aUnactivated alkyl halides in transitionmetalcatalyzed CH bond al cMAR  a3268-32920 v113 a

Alkylation represents an important organic transformation in molecular science to develop privileged alkylated arenes and heteroarenes. Especially, the direct C-H bond alkylation using unactivated alkyl halides is a straightforward and attractive approach from both the step-economy and chemoselectivity perspectives. Substantial progress has been made in the direct alkylation using primary, secondary, and tertiary alkyl halides along with the methylation and fluoroalkylation. This Review broadly summarizes the transition-metal-catalyzed alkylations of C-H bonds on various arenes and heteroarenes with unactivated alkyl halides until October 2020. On the basis of the substrates utilized for alkylation, the Review is divided into two major sections: alkylation of arenes and alkylation of heteroarenes.

10a(hetero)arenes10aAlkylation10aC-H activation10atransition metals10aunactivated alkyl halides1 aAnkade, Shidheshwar, B.1 aShabade, Anand, B.1 aSoni, Vineeta1 aPunji, Benudhar uhttps://library.ncl.res.in/content/unactivated-alkyl-halides-transition-metal-catalyzed-c-h-bond-alkylation02391nas a2200205 4500008004100000022001400041245013400055210006900189260000900258300001600267490000700283520164000290100002301930700002301953700001901976700002401995700001702019700002002036856012902056 2022 eng d a2041-652000aRoom temperature chemoselective hydrogenation of C=C, C=O and C=N bonds by using a well-defined mixed donor Mn(I) pincer catalyst0 aRoom temperature chemoselective hydrogenation of CC CO and CN bo cNOV  a13764-137730 v133 a

Chemoselective hydrogenation of C=C, C=O and C=N bonds in alpha,beta-unsaturated ketones, aldehydes and imines is accomplished at room temperature (27 degrees C) using a well-defined Mn(I) catalyst and 5.0 bar H-2. Amongst the three mixed-donor Mn(I) complexes developed, kappa(3)-((PNNPyz)-P-R2-N-3)Mn(CO)(2)Br (R = Ph, Pr-i, Bu-t); the Bu-t -substituted complex ((PNNPyz)-P-tBu2-N-3)Mn(CO)(2)Br shows exceptional chemoselective catalytic reduction of unsaturated bonds. This hydrogenation protocol tolerates a range of highly susceptible functionalities, such as halides (-F, -Cl, -Br, and -I), alkoxy and hydroxy, including hydrogen-sensitive moieties like acetyl, nitrile, nitro, epoxide, and unconjugated alkenyl and alkynyl groups. Additionally, the disclosed method applies to indole, pyrrole, furan, thiophene, and pyridine-containing unsaturated ketones leading to the corresponding saturated ketones. The C=C bond is chemoselectively hydrogenated in alpha,beta-unsaturated ketones, while the aldehyde's C=O bond and imine's C=N bond are preferentially reduced over the C=C bond. A detailed mechanistic study highlighted the non-innocent behavior of the ligand in the ((PNNPyz)-P-tBu2-N-3) Mn(I) complex and indicated a metal-ligand cooperative catalytic pathway. The molecular hydrogen (H-2) acts as a hydride source, whereas MeOH provides a proton for hydrogenation. DFT energy calculations supported the facile progress of most catalytic steps, involving a crucial turnover-limiting H-2 activation.

1 aShabade, Anand, B.1 aSharma, Dipesh, M.1 aBajpai, Priyam1 aGonnade, Rajesh, G.1 aVanka, Kumar1 aPunji, Benudhar uhttps://library.ncl.res.in/content/room-temperature-chemoselective-hydrogenation-cc-co-and-cn-bonds-using-well-defined-mixed01801nas a2200253 4500008004100000022001400041245012100055210007100176260000800247300001400255490000800269520091600277653001001193653002301203653002101226653002501247653001401272653002901286100002301315700002101338700002401359700002001383856014401403 2024 eng d a1615-415000aManganese-catalyzed chemoselective direct hydrogenation of α,β-epoxy ketones and α-ketoamides at room temperature0 aManganesecatalyzed chemoselective direct hydrogenation of αβepox cAUG a3338-33450 v3663 a

Chemoselective hydrogenation of alpha,beta-epoxy ketones and alpha-ketoamides is achieved at room temperature (25 degrees C) using 2.0 bar H-2 and a pincer-ligated Mn(I) catalyst that provides synthetically valuable alpha-hydroxy epoxides and alpha-hydroxy amides. This protocol applies to a wide range of alkyl- and aryl-substituted alpha,beta-epoxy ketones, including terpenes (alpha-ionone, nootkatone, and R-carvone)- and steroids (testosterone and progesterone)-derived epoxy ketones, and tolerates H-2 sensitive functionalities, such as halides, acetyl, nitrile, nitro, epoxide, alkenyl and alkynyl groups. Additionally, alpha-ketoamides bearing reducible functional groups, including acetyl and diazo benzene, were untouched under this protocol and selectively converted to alpha-hydroxy amides. A preliminary mechanistic study highlighted the metal-ligand cooperative H-2 activation process.

10aalpha10abeta-epoxy ketones10achemoselectivity10adirect hydrogenation10amanganese10aMetal-ligand cooperation1 aShabade, Anand, B.1 aSingh, Rahul, K.1 aGonnade, Rajesh, G.1 aPunji, Benudhar uhttps://library.ncl.res.in/content/manganese-catalyzed-chemoselective-direct-hydrogenation-%CE%B1%CE%B2-epoxy-ketones-and-%CE%B1-ketoamides