01890nas a2200241   4500008004100000022001400041245011100055210006900166260007300235300001200308490000800320520101700328653001101345653001201356653001301368653001901381653003001400653002101430100001901451700002101470700002801491856012901519       2005                        eng d  a1381-116900aCopper(II) ion-exchanged montmorillonite as catalyst for the direct addition of N-H bond to CC triple bond0 aCopperII ionexchanged montmorillonite as catalyst for the direct  aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcJUL  a139-1440 v2363 a<p>An efficient synthesis of phenyl-(1-phenylethylidene)amine using copper-exchanged montmorillonite clay (Cu K-10) is demonstrated. The catalyst was characterized using UV-vis, XRD, BET surface area measurements, pyridine adsorption etc. The XRD and surface area measurement show that the structural characteristics of the support montmorillonite K-10 (K-10) are preserved after Cu exchange. The hydroamination of phenyl acetylene with aniline was carried out in toluene under reflux condition in N-2 atmosphere at 393 K. The reaction is highly regio-selective for only Markovnikoff's addition of an-tine to CC multiple bond and proceeded smoothly to completion. The reaction conditions were optimized to obtain complete conversion with respect to phenyl acetylene. Reaction data showed that the activity of the catalyst in hydroamination reaction is greater at higher reaction temperatures and nonpolar solvents and NZ pressure promotes the reaction drastically. (c) 2005 Elsevier B.V. All rights reserved.</p>10aalkyne10aAniline10aCatalyst10ahydroamination10aK-10 montmorillonite clay10aphenyl acetylene1 aJoseph, Trissa1 aShanbhag, G., V.1 aHalligudi, Shivappa, B.  uhttps://library.ncl.res.in/content/copperii-ion-exchanged-montmorillonite-catalyst-direct-addition-n-h-bond-cc-triple-bond-002108nas a2200277   4500008004100000022001400041245013500055210006900190260009500259300001200354490000800366520111500374653001301489653001301502653001101515653001001526653002001536653001801556653001901574653001701593653001501610100002701625700001901652700002801671856013101699       2007                        eng d  a0021-951700aCopper(II) ion exchanged A1SBA-15: a versatile catalyst for intermolecular hydroamination of terminal alkynes with aromatic amines0 aCopperII ion exchanged A1SBA15 a versatile catalyst for intermol  a525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USAbACADEMIC PRESS INC ELSEVIER SCIENCEcSEP  a274-2820 v2503 a<p>The hydroarnination reaction offers a very attractive route for the synthesis of alkylated amines and their derivatives with no byproduct formation. AISBA-15 was synthesized by isomorphous substitution of aluminum into the framework of SBA-15, which induces the Bronsted acid sites, and these were exchanged with metal ions such as Cu2+, Zn2+, and Pd2+. The catalysts were characterized by XRD, N-2-sOrption, SEM, TEM, acidity measurements by FT-IR pyridine adsorption, H-2-TPR, (27)AI MAS NMR, and Si-29 MAS NMR. Hydroamination of phenylacetylene (PhAc) with 2,4-xylidine has been used as a test reaction, which gave N-(1-phenylethylidene)-2,4-dimethylaniline with no byproduct formation. CuAlSBA-15 and CuAIMCM-41 showed around three times greater activity in hydroamination of PhAc compared with Cu-clay and Cu-beta, due to the moderate Lewis acidity of Cu2+ present in mesoporous supports. The performance of the CuAlSBA-15 was also determined with different alkynes and amines to evaluate the catalyst's general applicability in hydroamination reactions. (c) 2007 Elsevier Inc. All rights reserved.</p>10aA1SBA-1510aaddition10aalkyne10aAmine10aCopper catalyst10aheterogeneous10ahydroamination10aion exchange10aMesoporous1 aShanbhag, Ganapati, V.1 aJoseph, Trissa1 aHalligudi, Shivaraj, B.  uhttps://library.ncl.res.in/content/copperii-ion-exchanged-a1sba-15-versatile-catalyst-intermolecular-hydroamination-terminal-001165nas a2200217   4500008004100000022001400041245008600055210006900141260007500210300001400285490000600299520037200305653003700677653002800714653001600742653001100758653002700769100001900796700001900815856011300834       2011                        eng d  a0039-788100aEfficient convergent access to spiroketal segment of (+)-spiroxaline methyl ether0 aEfficient convergent access to spiroketal segment of spiroxaline  aRUDIGERSTR 14, D-70469 STUTTGART, GERMANYbGEORG THIEME VERLAG KGcAPR  a1137-11410 v23 a<p>Starting from trimethylsilylacetylene, a facile synthesis of optically pure spiroketal unit of (+)-spiroxaline methyl ether has been described. The synthesis entails stepwise alkylation and acylation of an alkyne with two different readily available chiral building blocks followed by the reductive in situ regio- and stereoselective spiroketalization pathway.</p>10a(+)-spiroketal segment synthesis10a(R)-gamma-valerolactone10a(R)-oxirane10aalkyne10anucleophilic reactions1 aSingh, Mandeep1 aArgade, N., P.  uhttps://library.ncl.res.in/content/efficient-convergent-access-spiroketal-segment-spiroxaline-methyl-ether-002612nas a2200241   4500008004100000022001400041245008600055210006900141260000900210490000700219520183600226653002502062653001102087653001802098653002102116653002302137653002002160653001902180100001702199700001902216700002402235856011102259       2024                        eng d  a1867-388000aIron in organometallic transformations: a sustainable substitute for noble metals0 aIron in organometallic transformations a sustainable substitute   cOCT 0 v163 a<p>Transition metal catalysis plays a pivotal role in chemical synthesis. Noble metals often grab significant attention in organometallic catalysis due to their high reactivity. However, the serious issues associated with these metals such as low abundance, toxicity, geopolitical limitations, and volatile prices are driving the scientific community to discover sustainable alternatives. In this context, iron appears to be the first choice as an alternative metal due to its unique properties, including a range of stable oxidation states, Lewis acidity, high abundance in the earth's crust, and low toxicity. Over the past two decades, substantial progress has been made in iron catalysis. This overview examines the recent developments in iron-catalyzed industrially relevant transformations such as hydroformylation, olefin isomerization, hydrosilylation, hydrophosphination, carbonylation, Wacker-type oxidation, and plastic depolymerization. As witnessed throughout this review, the performance of iron can be significantly altered by suitable ligand selection and by tailoring the electronic and steric properties of the iron center. While noble metals remain the industry work-horse, iron is inching closer and with extensive scientific understanding, it may replace noble metals in the near future. Late transition metals catalyze several reactions and have been the industry work-horse for decades. While, earth abundant metals are rarely used in industrially relevant transformations. In this overview, we examine the recent development in iron-catalyzed industrially relevant reactions such as hydroformylation, olefin isomerization, hydrosilylation, hydrophosphination, carbonylation, Wacker-type oxidation, and plastic depolymerization. Iron is inching closer and may replace noble metals in near future. image</p>
10aAlkene Isomerization10aalkyne10aCarbonylation10adepolymerization10aHydrophosphination10aHydrosilylation10airon catalysis1 aKumar, Rohit1 aTewari, Tanuja1 aChikkali, Samir, H.  uhttps://library.ncl.res.in/content/iron-organometallic-transformations-sustainable-substitute-noble-metals01592nas a2200217   4500008004100000022001400041245009300055210006900148260000800217490000700225520086500232653002101097653001101118653001801129653001401147653002201161100002501183700002201208700002001230856012401250       2024                        eng d  a1861-472800aLigand-free MnBr2-catalyzed chemo- and stereoselective hydroboration of terminal alkynes0 aLigandfree MnBr2catalyzed chemo and stereoselective hydroboratio  cMAY0 v193 a<p>
	Developing simple and benign protocols for synthesizing alkenylboronates is crucial as they are synthetically valuable compounds in various organic transformations. In this work, we report a straightforward ligand-free protocol for synthesizing alkenylboronates via atom-economical hydroboration of alkynes with HBpin catalyzed by a manganese salt. The reaction shows a high level of chemo and regioselectivity for the terminal alkynes and exclusively produces E-selective alkenylboronates. The hydroboration scope is vast, with the resilience of a range of synthetically beneficial functionalities, such as halides, ether, alkenyl, silyl and thiophenyl groups. This reaction proceeds through the involvement of a metal-hydride intermediate. The developed alkenylboronate can be smoothly converted to useful C-C, C-N and C-I bond-forming reactions.</p>
10aalkenylboronates10aalkyne10aHydroboration10amanganese10astereoselectivity1 aPawar, Rameshwar, B.1 aKarmur, Mital, H.1 aPunji, Benudhar  uhttps://library.ncl.res.in/content/ligand-free-mnbr2-catalyzed-chemo-and-stereoselective-hydroboration-terminal-alkynes