@article { ISI:000254948900017, title = {Simple and efficient one-pot, three-component, solvent-free synthesis of beta-enaminones via sonogashira coupling-Michael addition sequences}, journal = {Synthetic Communications}, volume = {38}, number = {9}, year = {2008}, month = {APR}, pages = {1456-1469}, publisher = {TAYLOR \& FRANCIS INC}, address = {325 CHESTNUT ST, SUITE 800, PHILADELPHIA, PA 19106 USA}, abstract = {

A simple, efficient, and environmentally friendly one-pot, three-component synthesis of beta-enaminones via Sonogashira coupling-Michael addition sequences under solvent-free conditions has been reported. Also the synthesis of beta-enaminones has been achieved in high yields by the direct reaction of amines with ynones under solvent-free conditions.

}, keywords = {Alkynes, beta-enaminones, coupling, Michael additions, solvent free, ynones}, issn = {0039-7911}, doi = {10.1080/00397910801914343}, author = {Palimkar, Sanjay S. and More, Vijaykumar S. and Srinivasan, Kumar V.} } @article { ISI:000296195400018, title = {Phosphine-mediated synthesis of 1,4-oxazepine- and 1,5-oxazocine-based sugar hybrids from deoxysugar azides}, journal = {Synthesis-Stuttgart}, volume = {21}, number = {21}, year = {2011}, month = {NOV}, pages = {3523-3529}, publisher = {GEORG THIEME VERLAG KG}, address = {RUDIGERSTR 14, D-70469 STUTTGART, GERMANY}, abstract = {

An efficient and convenient method was developed for the synthesis of novel 1,4-oxazepine- and 1,5-oxazocine-based sugar hybrids from readily available deoxysugar azides by means of tributylphosphine-mediated tandem reactions. The resulting glycoconjugates might be useful in increasing the diversity of sugar backbones, and could find applications as potential glycomimetics and in drug discovery.

}, keywords = {Alkynes, azides, carbohydrates, heterocycles, oxazepines, oxazocines, Tandem reactions}, issn = {0039-7881}, doi = {10.1055/s-0030-1260218}, author = {Kurhade, Suresh E. and Salunkhe, Videsh T. and Siddaiah, V. and Bhuniya, Debnath and Reddy, D. Srinivasa} } @article { ISI:000332804700003, title = {Contemporary avenues in catalytic P-H bond addition reaction: a case study of hydrophosphination}, journal = {Coordination Chemistry Reviews}, volume = {265}, year = {2014}, month = {APR}, pages = {52-73}, publisher = {ELSEVIER SCIENCE SA}, type = {Review}, address = {PO BOX 564, 1001 LAUSANNE, SWITZERLAND}, abstract = {

Remarkable advances and current state-of-the-art developments in catalytic hydrophosphination of alkenes and alkynes are reviewed. The challenges in constructing a C P bond with a special emphasis on metal catalysed (asymmetric) hydrophosphination are highlighted. Only those systems that unambiguously proceed via P H bond addition across a C-C/X (X = O, N, S) multiple bond have been covered in this overview. Reviewed examples support the assumption that either strongly chelating ligands or reaction products that act as ligands, enhance the rate of hydrophosphination. The asymmetric variant of this transformation allows installation of p-chiral [enantiomeric excess (ee) up to 82\%] as well as C-chiral (ee up to 99\%) centres. The limited spectroscopic, mechanistic data and OFT calculations point at two distinctly different mechanisms. In case of hydrophosphination, the metal undergoes oxidative addition and reductive elimination steps (in general), thus changing the oxidation state from M(0) to M(II) and back to M(0). Whereas in asymmetric hydrophosphination it is proposed that the oxidation state of the metal remains unaltered throughout the catalytic cycle. The examples described in this overview showcase the real power of catalytic hydrophosphination in constructing various phosphorus compounds, which may initiate a new era in organo-phosphorus chemistry. (C) 2014 Elsevier B.V. All rights reserved.

}, keywords = {Alkynes, Asymmetric hydrophosphination, Hydrophosphination, Metal catalyzed hydrophosphination, Olefins, P-H bond addition}, issn = {0010-8545}, doi = {10.1016/j.ccr.2014.01.006}, author = {Koshti, Vijay and Gaikwad, Shahaji R. and Chikkali, Samir H.} } @article {47290, title = {3 d transition metal-catalyzed hydrogenation of nitriles and alkynes}, journal = {Chemistry-An Asian Journal}, volume = {15}, year = {2020}, month = {MAR}, pages = {690-708}, type = {Review}, abstract = {

Selective hydrogenation of nitriles and alkynes is crucial considering the vast applications of reduced products in industries and in the synthesis of bioactive compounds. Particularly, the late 3d transition metal catalysts (manganese, iron, cobalt, nickel and copper) have shown promising activity for the hydrogenation of nitriles to primary amines, secondary amines and imines. Similarly, semihydrogenation of alkynes to E- and Z-alkenes by 3d metals is adequately successful both via the transfer hydrogenation and by using molecular hydrogen. The emergence of 3d transition metals in the selective synthesis of industrially relevant amines, imines and alkenes makes this protocol more attractive. Herein, we provide a concise overview on the late 3d transition metal-catalyzed hydrogenation of nitriles to amines and imines as well as semihydrogenation of alkynes to alkenes.

}, keywords = {3d transition metal, Alkynes, Hydrogenation, nitriles, Semihydrogenation}, issn = {1861-4728}, doi = {10.1002/asia.201901762, Early Access Date = FEB 2020}, author = {Sharma, Dipesh M. and Punji, Benudhar} } @article {48311, title = {Iron-catalyzed magnesium-mediated formal hydroformylation of alkynes and alkenes}, journal = {ChemCatChem}, volume = {15}, year = {2023}, month = {FEB }, type = {Article}, abstract = {

Alkynes and alkenes are routinely converted to corresponding synthetically versatile aldehydes using rhodium-catalyzed hydroformylation. However, rhodium is rare, precious, costly, and depleting at a considerably high rate. Reported here is iron-catalyzed, magnesium-mediated, formal hydroformylation of alkynes and alkenes in the absence of syngas. Readily available FeCl2 in the presence of alkyl magnesium halide, and dimethyl formamide, catalyzes hydroformylation of various alkynes and selectively produces alpha,beta-unsaturated aldehydes in good to excellent conversion. Mechanistic investigations revealed the presence of vinyl magnesium intermediate, the kinetic study disclosed the first-order dependence of the reaction on iron loading, and the control experiment authenticated the iron catalyst{\textquoteright}s homogeneous nature. The scope of this methodology was amplified, and 20 alkenes were examined. [Fe(acac)(3)] in the presence of ligand, alkyl magnesium halide, and dimethyl formamide catalyzed the hydroformylation of alkenes and displayed good to excellent conversion. An earth-abundant iron catalyst offering a syngas cylinder-free safe alternative to high-pressure hydroformylation has been reported.

}, keywords = {aldehydes, alkenes, Alkynes, Hydroformylation, iron catalysis}, issn = {1867-3880}, doi = {10.1002/cctc.202201394}, author = {Tewari, Tanuja and Kumar, Rohit and Chikkali, Samir H.} } @article {49960, title = {(NHC-olefin)-nickel(0) nanoparticles: an efficient and selective catalyst for hydrogenation reactions at low temperature and pressure}, journal = {Journal of Catalysis}, volume = {453}, year = {2026}, month = {JAN}, pages = {116487}, type = {Article}, abstract = {

The reduction of a NHC-cinnamyl nickel(II) organometallic complex through the use of different MeMgBr or MeMgCl reagents led to two types of NHC-olefin-coordinated nickel nanoparticles. Both of these unsupported nickel-NHC based nanomaterials behaved under hydrogen pressure as effective and selective catalysts operating at low temperature (\<= 80 degrees C), pressure (\<= 20 bar) and loading (\<= 6 mol\%) for the reductions of broad scopes of alkenes, alkynes, imines and heterocycles, including a challenging tetra-substituted alkene. Among these two nickel-NHC nanocatalysts, the one generated with MeMgCl showed a significant high catalytic activity with high yields and could stand the comparison with Raney nickel and state-of-the-art nickel nanocatalysts. For example, by studying the hydrogenation of 1-phenylcyclohexene in ethanol at 60 degrees C under 10 bar of H2, 3 mol\% of this catalyst achieved the reaction within a single hour on a 5 mmol/0.8 g substrate scale with a yield of 96 \%, a turnover number (TON) of 32 and a turnover frequency (TOF) of 32. Characterizations confirmed the coordination of the NHC-olefin ligands to the nickel nanoparticles, the reduced state of the nickel and the (poly-) crystallinity of the nanoparticles.

}, keywords = {alkenes, Alkynes, heterocycles, Hydrogenation, imines, N -heterocyclic carbene ligand, nanocatalysis, Nickel}, issn = {0021-9517}, doi = {10.1016/j.jcat.2025.116487}, author = {Avello, Marta G. and Singh, Geetika and Truong-Phuoc, Lai and Vidal, Loic and Papaefthimiou, Vasiliki and Chesse, Matthieu and Gruber, Nathalie and Chetcuti, Michael J. and Vanka, Kumar and Ritleng, Vincent and Pham-Huu, Cuong and Michon, Christophe} }