01674nas a2200229 4500008004100000022001400041245008100055210006900136260006900205300000900274490000800283520084100291653003201132653002701164653002501191653002501216653001201241100002401253700003001277700002301307856011401330 2014 eng d a0010-854500aHybrid diphosphorus ligands in rhodium catalysed asymmetric hydroformylation0 aHybrid diphosphorus ligands in rhodium catalysed asymmetric hydr aPO BOX 564, 1001 LAUSANNE, SWITZERLANDbELSEVIER SCIENCE SAcMAR a1-150 v2623 a

This review aims to illustrate recent advances in the application of hybrid diphosphorus ligands for the Rh catalysed hydroformylation of alkenes, discussing the most prevalent classes of hybrid systems, i.e. phosphine-phosphinite, phosphine-phosphonite, phosphine-phosphite, phosphite-phosphoramidite and phosphite-phosphoramidite and comparing their performance with relevant C-2 symmetric counterparts. In order to introduce the field and put the results in context, a short overview on Rh hydroformylation is provided. Available spectroscopic (in situ) data on the coordination modes of hybrid phosphorus ligands and the catalytic performance of these systems in asymmetric hydroformylation of vinyl arenes are reported. Potential avenues for future research are shortly discussed. (C) 2013 Elsevier B.V. All rights reserved.

10aAsymmetric hydroformylation10aCatalyst resting state10aHybrid ligand design10aIn situ spectroscopy10aRhodium1 aChikkali, Samir, H.1 avan der Vlugt, Jarl, Ivar1 aReek, Joost, N. H. uhttp://library.ncl.res.in/content/hybrid-diphosphorus-ligands-rhodium-catalysed-asymmetric-hydroformylation-001888nas a2200181 4500008004100000022001400041245012600055210006900181260007100250300001400321490000700335520114600342100002201488700002101510700002401531700002401555856012701579 2015 eng d a0276-733300aHighly enantioselective Pd-catalyzed synthesis of P-stereogenic supramolecular phosphines, self-assembly, and implication0 aHighly enantioselective Pdcatalyzed synthesis of Pstereogenic su a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcOCT a4802-48050 v343 a

Metal-catalyzed asymmetric addition of a secondary phosphine to an aryl halide is one of the most efficient and reliable approaches for the construction of enantiopure carbon phosphorus bonds. An isolated Pd(II) complex (5) catalyzes the carbon phosphorus coupling reaction between tolylphenylphosphine (la) and 3-iodophenylurea (2b), which proceeds with an unprecedented enantiomeric excess (ee) of 97%. The generality of the strategy has been demonstrated by preparing a small library of a new class of P-stereogenic phosphines with an in-built hydrogen bonding motif for the first time. The P-stereogenic phosphines self-assemble on a metal template via deliberately installed hydrogen-bonding motifs and mimic the bidentate ligand coordination. Interestingly, when it was employed in asymmetric hydrogenation, the supramolecular phosphine {1-(3-(phenyl(o-toly)phosphanyl)pheny)ureal} (6b) produced the corresponding hydrogenated product with the highest enantiomeric excess of 99% along with excellent conversion, demonstrating the potential of these enantioenriched P-chirogenic supramolecular phosphines in asymmetric catalysis.

1 aKoshti, Vijay, S.1 aMote, Nilesh, R.1 aGonnade, Rajesh, G.1 aChikkali, Samir, H. uhttp://library.ncl.res.in/content/highly-enantioselective-pd-catalyzed-synthesis-p-stereogenic-supramolecular-phosphines-101457nas a2200217 4500008004100000022001400041245013200055210006900187260007500256300001400331490000600345520063000351653001200981653002000993653002101013653001801034653001201052100002201064700002401086856012901110 2015 eng d a1867-388000aHighly regioselective isomerizing hydroformylation of long-chain internal olefins catalyzed by a rhodium bis(phosphite) complex0 aHighly regioselective isomerizing hydroformylation of longchain  aPOSTFACH 101161, 69451 WEINHEIM, GERMANYbWILEY-V C H VERLAG GMBHcNOV a3468-34710 v73 a

The single-step synthesis, coordination behavior, and application of a bis(phosphite) ligand in the isomerizing hydroformylation of internal olefins was investigated. Interestingly, high-pressure NMR spectroscopy investigations revealed unexpected inequivalency of the two phosphorus nuclei, which display bisequatorial coordination of the bis(phosphite) ligand in a trigonal bipyramidal rhodium complex. Upon employment in the isomerizing hydroformylation of the exceedingly challenging plant oil derived substrate methyl oleate, the bis(phosphite) rhodium complex revealed an unprecedented linear selectivity of 75%.

10aalkenes10abis(phosphite)s10aHydroformylation10aisomerization10aRhodium1 aPandey, Swechchha1 aChikkali, Samir, H. uhttp://library.ncl.res.in/content/highly-regioselective-isomerizing-hydroformylation-long-chain-internal-olefins-catalyzed-002516nas a2200205 4500008004100000245015200041210006900193260000800262300001600270490000700286520173400293100002102027700001702048700002302065700002502088700002202113700002402135700002402159856012702183 2017 eng d00aH-Bonding assisted self-assembly of anionic and neutral ligand on metal: a comprehensive strategy to mimic ditopic ligands in olefin polymerization0 aHBonding assisted selfassembly of anionic and neutral ligand on  cOCT a12448-124560 v563 aSelf-assembly of two neutral ligands on a metal to mimic bidentate ligand coordination has been frequently encountered in the recent past, but self-assembly of an anionic ligand on a metal template alongside a neutral ligand remains an elusive target. Such a self-assembly is hampered by additional complexity, wherein a highly negatively charged anion can form intermolecular hydrogen bonding with the supramolecular motif, leaving no scope for self-assembly with neutral ligand. Presented here is the self-association of anionic ligand 3-ureidobenzoic acid (2a) and neutral ligand 1-(3-(diphenylphosphanyl)phenyl)urea (1a) on a metal template to yield metal complex [{COOC6H4-NH(CO)NH2}{Ph2PC6H4NH(CO)NH2}PdMeDMSO] (4a). The identity of 4a was established by NMR and mass spectroscopy. Along the same lines, 3-(3-phenylureido)benzoic acid (2b) and 1-(3-(diphenylphosphanyl)phenyl)-3-phenylurea (1b) self-assemble on a metal template to produce palladium complex [{COOC6H4NH(CO)NHPh}{Ph2PC6H4NH(CO)NHPh}PdMePy] (5c). The existence of 5c was confirmed by Job plot, 1-2D NMR spectroscopy, deuterium labeling, IR spectroscopy, UV-vis spectroscopy, model complex synthesis, and DFT calculations. These solution and gas phase investigations authenticated the presence of intramolecular hydrogen bonding between hydrogen's of 1b and carbonyl oxygen of 2b. The generality of the supramolecular approach has been validated by preparing six complexes from four monodentate ligands, and their synthetic utility was demonstrated in ethylene polymerization. Complex 4a was found to be the most active, leading to the production of highly branched polyethylene with a molecular weight of 55700 g/mol and melting temperature of 112 degrees C.1 aMote, Nilesh, R.1 aPatel, Ketan1 aShinde, Dinesh, R.1 aGaikwad, Shahaji, R.1 aKoshti, Vijay, S.1 aGonnade, Rajesh, G.1 aChikkali, Samir, H. uhttp://library.ncl.res.in/content/h-bonding-assisted-self-assembly-anionic-and-neutral-ligand-metal-comprehensive-strategy01880nas a2200157 4500008004100000022001500041245006200056210006200118260000800180300001400188490000700202520137200209100002101581700002401602856009601626 2018 eng d a 1861-472800aHydrogen bonding assissted supramolecular metal catalysis0 aHydrogen bonding assissted supramolecular metal catalysis cDEC a3623-36460 v133 aThe process of catalyst screening and discovery still largely relies on traditional ligand-design approaches, which suffer from complex synthetic requirements and offer limited structural diversity. On the contrary, supramolecular chemistry offers the potential to harness multiple weak secondary interactions to deliver self-assembled catalysts with diverse structures or to orient substrates to achieve enzyme-like activity and selectivity. Herein, the application of hydrogen-bonding (H-bonding) interactions as a construction element and directing group in "supramolecular transition-metal catalysis" is critically reviewed and the current state-of-the-art in the field is presented. H-bonding interactions empower structurally simple ligands to deliver complex self-assembled catalysts, which have been found to catalyze a gamut of organic transformations, including hydroformylation, hydrogenation, and allylation reactions. As we will discuss, on many occasions, these supramolecular catalysts outperform their analogous covalently linked catalytic systems. The potential of H-bonding interactions as directing groups has recently been recognized by the scientific community and this Focus Review presents the role of hydrogen-bonding interactions in directing substrates to obtain excellent selectivities and activities in a range of catalytic transformations1 aMote, Nilesh, R.1 aChikkali, Samir, H. uhttp://library.ncl.res.in/content/hydrogen-bonding-assissted-supramolecular-metal-catalysis01876nas a2200157 4500008004100000022001500041245006100056210005900117260000800176300001400184490000700198520137300205100002101578700002401599856009501623 2018 eng d a1861-4728 00aHydrogen-bonding-assisted supramolecular metal catalysis0 aHydrogenbondingassisted supramolecular metal catalysis cDEC a3623-36460 v133 aThe process of catalyst screening and discovery still largely relies on traditional ligand-design approaches, which suffer from complex synthetic requirements and offer limited structural diversity. On the contrary, supramolecular chemistry offers the potential to harness multiple weak secondary interactions to deliver self-assembled catalysts with diverse structures or to orient substrates to achieve enzyme-like activity and selectivity. Herein, the application of hydrogen-bonding (H-bonding) interactions as a construction element and directing group in "supramolecular transition-metal catalysis" is critically reviewed and the current state-of-the-art in the field is presented. H-bonding interactions empower structurally simple ligands to deliver complex self-assembled catalysts, which have been found to catalyze a gamut of organic transformations, including hydroformylation, hydrogenation, and allylation reactions. As we will discuss, on many occasions, these supramolecular catalysts outperform their analogous covalently linked catalytic systems. The potential of H-bonding interactions as directing groups has recently been recognized by the scientific community and this Focus Review presents the role of hydrogen-bonding interactions in directing substrates to obtain excellent selectivities and activities in a range of catalytic transformations.1 aMote, Nilesh, R.1 aChikkali, Samir, H. uhttp://library.ncl.res.in/content/hydrogen-bonding-assisted-supramolecular-metal-catalysis01240nas a2200289 4500008004100000022001400041245005300055210005300108260000800161300001200169490000600181520040000187653002900587653001400616653002200630653001200652653001600664100002000680700001700700700002700717700002400744700002500768700002500793700002400818700002400842856008400866 2020 eng d a2193-580700aHighly enantioselective synthesis of sitagliptin0 aHighly enantioselective synthesis of sitagliptin cFEB a189-1910 v93 a

A highly enantioselective synthesis of sitagliptin, a potent DPP-4 inhibitor, is reported. Explicitly identified chiral FerroLANE ligands in the presence of rhodium catalyze the asymmetric hydrogenation of an enamine to yield sitagliptin with excellent enantioselectivity (98% ee). The process was scaled up to 5 g and the final product was isolated as a phosphate salt with >99% ee.

10aasymmetric hydrogenation10acatalysis10aFerroLANE ligands10aRhodium10asitagliptin1 aKhopade, Kishor1 aSen, Anirban1 aBirajdar, Rajkumar, S.1 aPaulbudhe, Uday, P.1 aKavale, Dattatry, S.1 aShinde, Prashant, S.1 aMhaske, Santosh, B.1 aChikkali, Samir, H. uhttp://library.ncl.res.in/content/highly-enantioselective-synthesis-sitagliptin01990nas a2200217 4500008004100000022001400041245006100055210006100116260000800177300001100185490000800196520135900204653001401563653001201577653001401589653002101603653002301624100001701647700002401664856008401688 2022 eng d a0022-328X00aHydroformylation of olefins by metals other than rhodium0 aHydroformylation of olefins by metals other than rhodium cFEB a1222310 v9603 aMetal catalyzed hydroformylation of alkenes is an atom economic transformation to construct useful aldehydes and is being industrially practiced for decades. The most commonly used metal for this transformation on an industrial scale is rhodium. However, rhodium is rare, costly, and is depleting at a skyrocketing rate. Therefore, finding a suitable alternative to rhodium for metal-catalyzed hydroformylation has been on the radar of many academic and industrial researchers. This review presents the scientific advancements reported in the hydroformylation reaction using metals other than rhodium. An overview of recent progress in palladium, iridium, ruthenium, cobalt, platinum, and iron-catalyzed hydroformylation is presented. Hydroformylation of alkenes and alkynes, using syngas as well as syngas surrogates is examined. The evaluation of the current status of non-rhodium metals in hydroformylation suggests that the field is still in a nascent stage and, except cobalt, no other metal poses a significant challenge to the dominance of rhodium. Deep mechanistic understanding of rate-limiting elementary steps in the non-rhodium metals is largely missing and thus only limited success is reported. Intense research on ligand design, mechanistic understanding, and choice of non-rhodium metal precursors may change this scenario in near future.10aaldehydes10aalkenes10acatalysis10aHydroformylation10aNon-rhodium metals1 aKumar, Rohit1 aChikkali, Samir, H. uhttp://library.ncl.res.in/content/hydroformylation-olefins-metals-other-rhodium