@article {Shanbhag, title = {Enantioselective syntheses of (-)-pinellic acid, alpha- and beta-dimorphecolic acid}, journal = {Tetrahedron}, volume = {63}, number = {32}, year = {2007}, month = {AUG}, pages = {7624-7633}, publisher = {PERGAMON-ELSEVIER SCIENCE LTD}, type = {Article}, address = {THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND}, abstract = {

An efficient enantioselective convergent approach for the synthesis of (-)-pinellic acid 1, alpha- and beta- dimorphecolic acid (2 and 3) from 1,9-nonane diol is described. The synthetic strategy features Sharpless asymmetric hydroxylation, Sonogashira coupling and Birch reduction. (C) 2007 Elsevier Ltd. All rights reserved.

}, keywords = {asymmetric dihydroxylation, influenza, Sonogashira coupling}, issn = {0040-4020}, doi = {10.1016/j.tet.2007.05.047}, author = {Baruah, Pranjal K. and Gonnade, Rajesh G. and Sanjayan, Gangadhar J.} } @article { ISI:000271713300024, title = {Influence of electronic factors on pd-mediated cycloisomerization: a systematic investigation of competitive 6-exo-dig versus 7-endo-dig cyclizations of sugar alkynols}, journal = {Tetrahedron}, volume = {65}, number = {47}, year = {2009}, month = {NOV}, pages = {9819-9832}, publisher = {PERGAMON-ELSEVIER SCIENCE LTD}, address = {THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND}, abstract = {

Pd-mediated cycloisomerization of 3-C-propargyl-ribo- and allofuranose derivatives was investigated in detail to understand the influence of electronic factors on the regioselectivity (6-exo- vs 7-endo) of alkynol cycloisomerization leading either to a six- or seven-membered ring. In general, the 6-exo-dig mode of cyclization is facile and is independent of electronic factors. With some of the alkynols, a regioselective (7-endo?) hydration of the alkyne unit was observed and this has been attributed to the participation of C(3)-OH. When the C(3)-OH was protected as its benzyl ether, cycloisomerization of these alkynols occurred exclusively in a 6-exo-dig mode resulting in the corresponding [3.2.1]-bicyclic ketals. Additional control experiments conducted were in support of the participation of C(3)-OH in regioselective alkyne hydration. (C) 2009 Elsevier Ltd. All rights reserved.

}, keywords = {Alkynol cycloisomerization, Bridged bicyclic ketal, Palladium, Sonogashira coupling, Sugar alkynol}, issn = {0040-4020}, doi = {10.1016/j.tet.2009.09.071}, author = {Ramana, C. V. and Induvadana, Boddeti and Srinivas, Burgula and Yadagiri, Kommagalla and Deshmukh, Madhusudhan N. and Gonnade, Rajesh G.} } @article { ISI:000273066200048, title = {Modular total synthesis of aculeatins A, B, E, F and 6-epi-aculeatins E, F}, journal = {Tetrahedron}, volume = {66}, number = {1}, year = {2010}, month = {JAN}, pages = {390-399}, publisher = {PERGAMON-ELSEVIER SCIENCE LTD}, address = {THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND}, abstract = {

The total synthesis of aculeatins A, B. E and F confirming the assigned absolute configuration of recently isolated aculeatins E and F is documented. A convergent approach has been designed by the addition of both the terminal units (phenol and side chain) at an advanced stage. The central 1,3,5-triol unit with the requisite stereochemistry was prepared from the commercially available alpha-D-glucoheptonic-gamma-lactone. Selective O-debenzylation during the hydrogenolysis of the diyne intermediate and the one pot phenolic oxidation with concomitant spiroketalization highlight the accomplished total syntheses. (C) 2009 Elsevier Ltd. All rights reserved.

}, keywords = {aculeatins, Alkyne-oxirane coupling, Natural products synthesis, Oxidative spiroketalization, Sonogashira coupling}, issn = {0040-4020}, doi = {10.1016/j.tet.2009.10.058}, author = {Ramana, C. V. and Pandey, Sunil Kumar} } @article {48120, title = {Highly efficient and reusable polymer supported palladium catalyst for copper free sonogashira reaction in water}, journal = {ChemistrySelect}, volume = {7}, year = {2022}, month = {APR}, pages = {e202104273}, type = {Article}, abstract = {

Development of a novel, greener and efficient heterogeneous catalytic system for copper free Sonogashira reaction in water is described. This novel catalyst can be easily prepared by a simple method through synthetic modification of nitrile group in Polyacrylonitrile (PAN) using monoethanolamine (MEA) followed by its complexation with palladium chloride (PdCl2). The resulting polymer Pd complex (mPAN-Pd) was characterized by means of Fourier Transform Infrared Spectroscopy (FTIR), Energy-Dispersive X-ray Spectroscopy (EDAX), Inductively Coupled Mass Spectrometry (ICP-MS) and X-ray Photo Electron Spectroscopy (XPS) analyses. mPAN-Pd was then explored as highly efficient heterogeneous catalyst for Sonogashira coupling reaction under copper and ligand free conditions in water affording the corresponding coupling products up to 97 \% isolated yield. Moreover, the catalyst was recovered by simple filtration after the reaction and reused for next 5 cycles with excellent stability and activity. This is the first report on the use of ethanolamine modified PAN Pd (II) complex as an efficient heterogeneous catalyst for a coupling reaction.

}, keywords = {catalysis, green chemistry, Palladium, Polymer Support, Sonogashira coupling}, issn = {2365-6549}, doi = {10.1002/slct.202104273}, author = {Sruthi, Pambingal Rajan and Nimmi, Puthan Purayil and Babu, Sukumaran Santhosh and Anas, Saithalavi} } @article {48290, title = {Organic field effect transistors comprising copolymers synthesized without structure-directing moieties with enhanced carrier mobility}, journal = {ACS Applied Electronic Materials}, volume = {5}, year = {2023}, month = {APR}, pages = {2338-2344}, type = {Article}, abstract = {

Conjugated materials are synthesized by C-C bond formation reactions. Trimethyltin and boronic acid are two widely used structure-directing moieties. While using the ethynyl moiety as a part of the monomer, additional structure-directing moieties are not needed. However, ethynylene will be part of the conjugated material. Often, the polymers with an ethynylene moiety negatively impact the polymers{\textquoteright} properties. However, the ethynylene moiety could minimize the dihedral angle if the monomer has steric functionalities. For example, BODIPY is an attractive monomer due to its high molar extinction coefficient, partial quinoidal character, and high quantum yield. However, materials based on BODIPY exhibited poor charge carrier mobility due to steric hindrance generated by four methyl groups. Herein, we copolymerize BODIPY with ethynylene comprising i-indigo and thieno-i-indigo. The copolymer with thieno-i-indigo showed increased molecular weight and significantly reduced band gap compared to the copolymer with i-indigo. The copolymer with i-indigo showed immeasurably low hole transport mobility. On the other hand, the copolymer with thieno-i-indigo exhibited 0.003 cm2V(-1) s(-1). These measurements were made using field effect transistors. We also measured the charge carrier mobility using the space charge-limited current method. Both copolymers exhibited a mobility of 10(-3) cm(2) V-1 s(-1).

}, keywords = {acetylene linkage, BODIPY, field effect transistor, iso-indigo, Sonogashira coupling, thienoisoindigo}, doi = {10.1021/acsaelm.3c00160}, author = {Swain, Gitanjali and Javaregowda, Bharathkumar H. and Dambhare, Neha V. and Krishnamoorthy, Kothandam} } @article {49647, title = {ZrO2 supported Cu nanoparticles for sonogashira and ullmann coupling reactions under palladium-free conditions}, journal = {Catalysis Letters}, volume = {154}, year = {2024}, month = {JUN}, pages = {3078-3090}, type = {Article}, abstract = {

Cu nanoparticles supported on ZrO2 (CuNPs@ZrO2) were synthesized using a one-step co-precipitation process, and their application in C-C coupling reactions was investigated. The catalyst was characterized using XRD, XPS, SEM, TEM, and TGA techniques. The prepared catalyst was used for the Sonogashira cross-coupling reactions of aryl bromides with phenyl-acetylene in the presence of K2CO3 in DMF at 110 degrees C, which resulted in substituted alkynes with good to excellent yields. The protocol was also extended for the Ullmann coupling reactions of aryl iodides under similar reaction conditions, yielding the desired products with good to excellent yields without homo-coupling. Interestingly, unlike other copper catalysts, the present catalyst worked under air and did not require an inert atmosphere to prevent alkyne. This catalytic system is versatile, tolerant, and significantly cheaper than the {\textquoteleft}{\textquoteleft}traditional{\textquoteright}{\textquoteright} Pd-catalyzed Sonogashira cross-coupling of terminal alkynes with aryl halides. The catalyst could be reused for five catalytic cycles with no significant change in the product yield. All of these characteristics make our prepared CuNPs@ZrO2 catalyst quite suitable for the gram-scale synthesis of biaryls and alkynes, with a simple workup.{GRAPHIACAL ABSTRACT

}, keywords = {CuNPs, Recyclability, Sonogashira coupling, Ullmann coupling, ZrO2}, issn = {1011-372X}, doi = {10.1007/s10562-023-04513-w}, author = {Patil, Seema P. and Rajmane, Archana S. and Jadhav, Sanjay N. and Rajmane, Vijaya S. and Rode, Chandrashekhar V. and Kumbhar, Arjun S.} }