Pure Appl. Chem., 2001, Vol. 73, No. 8, pp. 1319-1324
http://dx.doi.org/10.1351/pac200173081319
Recoverable catalysts. Ultimate goals, criteria of evaluation, and the green chemistry interface
CrossRef Cited-by Linking
- Bae Il Hak, Lee In-Hwan, Byun Sangmoon, Chung Jooyoung, Kim B. Moon, Choi Tae-Lim: Magnetically recyclable Pd-Fe3 O4 heterodimer nanocrystals for the synthesis of conjugated polymers via suzuki polycondensation: Toward green chemistry. J. Polym. Sci. Part A: Polym. Chem. 2014, n/a. <http://dx.doi.org/10.1002/pola.27168>
- Siddiqui Zeba N., Khan Kulsum, Ahmed Nayeem: Nano Fibrous Silica Sulphuric Acid as an Efficient Catalyst for the Synthesis of β-Enaminone. Catal Lett 2014, 144, 623. <http://dx.doi.org/10.1007/s10562-013-1190-4>
- Bergbreiter David E.: Soluble Polymers as Tools in Catalysis. ACS Macro Lett. 2014, 3, 260. <http://dx.doi.org/10.1021/mz500075b>
- Schröder Kristin, Matyjaszewski Krzysztof, Noonan Kevin J. T., Mathers Robert T.: Towards sustainable polymer chemistry with homogeneous metal-based catalysts. Green Chem. 2014, 16, 1673. <http://dx.doi.org/10.1039/c3gc42159g>
- Beejapur Hazi Ahmad, Giacalone Francesco, Noto Renato, Franchi Paola, Lucarini Marco, Gruttadauria Michelangelo: Recyclable Catalyst Reservoir: Oxidation of Alcohols Mediated by Noncovalently Supported Bis(imidazolium)-Tagged 2,2,6,6-Tetramethylpiperidine 1-Oxyl. ChemCatChem 2013, 5, 2991. <http://dx.doi.org/10.1002/cctc.201300234>
- Speziali Marcelo Gomes, Silva Anderson Gabriel Marques da, Miranda Débora Michelini Vaz de, Monteiro Adriano Lisboa, Robles-Dutenhefner Patricia Alejandra: Air stable ligandless heterogeneous catalyst systems based on Pd and Au supported in SiO2 and MCM-41 for Suzuki–Miyaura cross-coupling in aqueous medium. Applied Catalysis A: General 2013, 462-463, 39. <http://dx.doi.org/10.1016/j.apcata.2013.04.034>
- Bakherad Mohammad, Keivanloo Ali, Bahramian Bahram, Jajarmi Saeideh: Suzuki, Heck, and copper-free Sonogashira reactions catalyzed by 4-amino-5-methyl-3-thio-1,2,4-triazole-functionalized polystyrene resin-supported Pd(II) under aerobic conditions in water. Journal of Organometallic Chemistry 2013, 724, 206. <http://dx.doi.org/10.1016/j.jorganchem.2012.11.008>
- Kumbhar Arjun, Kamble Santosh, Mane Anand, Jha Ratnesh, Salunkhe Rajashri: Modified zeolite immobilized palladium for ligand-free Suzuki–Miyaura cross-coupling reaction. Journal of Organometallic Chemistry 2013, 738, 29. <http://dx.doi.org/10.1016/j.jorganchem.2013.03.031>
- Bakherad Mohammad, Jajarmi Saeideh: A dithizone-functionalized polystyrene resin-supported Pd(II) complex as an effective catalyst for Suzuki, Heck, and copper-free Sonogashira reactions under aerobic conditions in water. Journal of Molecular Catalysis A: Chemical 2013, 370, 152. <http://dx.doi.org/10.1016/j.molcata.2013.01.009>
- Karthikeyan Parasuraman, Vanitha Arumugam, Radhika Pachaiappan, Suresh Kannan, Sugumaran Arunachalam: Imidazolium supported palladium–chloroglycine complex: recyclable catalyst for Suzuki–Miyaura coupling reactions. Tetrahedron Letters 2013, 54, 7193. <http://dx.doi.org/10.1016/j.tetlet.2013.10.111>
- Ye Changming, Jin Peng, Liu Junxia, Wen Yiqiang, Wei Huijuan, Zheng Xiaoguang, Wang Xiangyu, Li Baojun: Process for Recycling Tungsten from the Leach Solution of Organic Oxidation Reaction Systems. Ind. Eng. Chem. Res. 2013, 130228111657007. <http://dx.doi.org/10.1021/ie301856s>
- Ghosh Partha Pratim, Das Asish R.: Nanocrystalline and Reusable ZnO Catalyst for the Assembly of Densely Functionalized 4H-Chromenes in Aqueous Medium via One-Pot Three Component Reactions: A Greener “NOSE” Approach. J. Org. Chem. 2013, 78, 6170. <http://dx.doi.org/10.1021/jo400763z>
- Kashin Alexey S., Ananikov Valentine P.: Catalytic C–C and C–Heteroatom Bond Formation Reactions: In Situ Generated or Preformed Catalysts? Complicated Mechanistic Picture Behind Well-Known Experimental Procedures. J. Org. Chem. 2013, 78, 11117. <http://dx.doi.org/10.1021/jo402038p>
- Ranganath Kalluri V. S., Onitsuka Satoaki, Kumar A. Kiran, Inanaga Junji: Recent progress of N-heterocyclic carbenes in heterogeneous catalysis. Catal. Sci. Technol. 2013, 3, 2161. <http://dx.doi.org/10.1039/c3cy00118k>
- Kalidindi Suresh Babu, Jagirdar Balaji R.: Nanocatalysis and Prospects of Green Chemistry. ChemSusChem 2012, 5, 65. <http://dx.doi.org/10.1002/cssc.201100377>
- Carreiro Elisabete P., Moura Nuno M. M., Burke Anthony J.: Covalent and Noncovalent Immobilization of Arylid-BOX Ligands and Their Derivatives: Evaluation in the Catalytic Asymmetric Cyclopropanation of Styrenes. Eur J Org 2012, 2012, 518. <http://dx.doi.org/10.1002/ejoc.201100781>
- Sharghi Hashem, Aberi Mahdi, Doroodmand Mohammad Mahdi: One-pot synthesis of 2-arylbenzimidazole, 2-arylbenzothiazole and 2-arylbenzoxazole derivatives using vanadium(IV)–salen complex as homogeneous catalyst and vanadium(IV)–salen complex nanoparticles immobilized onto silica as a heterogeneous nanocatalyst. J IRAN CHEM SOC 2012, 9, 189. <http://dx.doi.org/10.1007/s13738-011-0045-4>
- Sans V., Gelat F., Burguete M.I., Garcia-Verdugo E., Luis S.V.: Polymer-supported Pd–NHC complexes: Strategies for the development of multifunctional systems. Catalysis Today 2012, 196, 137. <http://dx.doi.org/10.1016/j.cattod.2012.03.036>
- Crabtree Robert H.: Resolving Heterogeneity Problems and Impurity Artifacts in Operationally Homogeneous Transition Metal Catalysts. Chemistry Review 2012, 112, 1536. <http://dx.doi.org/10.1021/cr2002905>
- Kozuch Sebastian, Martin Jan M. L.: “Turning Over” Definitions in Catalytic Cycles. ACS Catal. 2012, 2, 2787. <http://dx.doi.org/10.1021/cs3005264>
- Ananikov Valentine P., Beletskaya Irina P.: Toward the Ideal Catalyst: From Atomic Centers to a “Cocktail” of Catalysts. Organomettalics 2012, 31, 1595. <http://dx.doi.org/10.1021/om201120n>
- Kühbeck Dennis, Saidulu G., Reddy K. Rajender, Díaz David Díaz: Critical assessment of the efficiency of chitosan biohydrogel beads as recyclable and heterogeneous organocatalyst for C–C bond formation. Green Chem 2012, 14, 378. <http://dx.doi.org/10.1039/c1gc15925a>
- Gruttadauria Michelangelo, Liotta Leonarda Francesca, Salvo Anna Maria Pia, Giacalone Francesco, La Parola Valeria, Aprile Carmela, Noto Renato: Multi-Layered, Covalently Supported Ionic Liquid Phase (mlc-SILP) as Highly Cross-Linked Support for Recyclable Palladium Catalysts for the Suzuki Reaction in Aqueous Medium. Synth Catal 2011, 353, 2119. <http://dx.doi.org/10.1002/adsc.201100186>
- Li Chieh-Keng, Ghalwadkar Ajay, Lu Norman: Recoverable cationic Pd-catalyzed Heck reaction under thermomorphic mode. J Organomet Chem 2011, 696, 3637. <http://dx.doi.org/10.1016/j.jorganchem.2011.08.028>
- Singh Vasundhara, Ratti Rajni, Kaur Sukhbir: Synthesis and characterization of recyclable and recoverable MMT-clay exchanged ammonium tagged carbapalladacycle catalyst for Mizoroki–Heck and Sonogashira reactions in ionic liquid media. Journal of Molecular Catalysis A 2011, 334, 13. <http://dx.doi.org/10.1016/j.molcata.2010.10.015>
- NAGASHIMA Hideo: Chemistry of Metal Encapsulated Polysiloxane Gel as Reusable Catalysts. KOBUNSHI RONBUNSHU 2011, 68, 393. <http://dx.doi.org/10.1295/koron.68.393>
- Lamblin Marc, Nassar-Hardy Luma, Hierso Jean-Cyrille, Fouquet Eric, Felpin François-Xavier: Recyclable Heterogeneous Palladium Catalysts in Pure Water: Sustainable Developments in Suzuki, Heck, Sonogashira and Tsuji-Trost Reactions. Adv Synth Catal 2010, 352, 33. <http://dx.doi.org/10.1002/adsc.200900765>
- Sans Victor, Gelat Fabien, Karbass Naima, Burguete M. Isabel, García-Verdugo Eduardo, Luis Santiago V.: Polymer Cocktail: A Multitask Supported Ionic Liquid-Like Species to Facilitate Multiple and Consecutive CC Coupling Reactions. Adv Synth Catal 2010, 352, 3013. <http://dx.doi.org/10.1002/adsc.201000528>
- Shylesh Sankaranarayanapillai, Schünemann Volker, Thiel Werner R.: Magnetisch abtrennbare Nanokatalysatoren: Brücken zwischen homogener und heterogener Katalyse. Angew. Chem. 2010, 122, 3504. <http://dx.doi.org/10.1002/ange.200905684>
- Shylesh Sankaranarayanapillai, Schünemann Volker, Thiel Werner R.: Magnetically Separable Nanocatalysts: Bridges between Homogeneous and Heterogeneous Catalysis. Angew Chem Int Ed 2010, 49, 3428. <http://dx.doi.org/10.1002/anie.200905684>
- Zhu Xunjin, Venkatasubbaiah Krishnan, Weck Marcus, Jones Christopher W.: Kinetic Evaluation of Cooperative [Co(salen)] Catalysts in the Hydrolytic Kinetic Resolution of rac-Epichlorohydrin. ChemCatChem 2010, 2, 1252. <http://dx.doi.org/10.1002/cctc.201000162>
- Somorjai Gabor A., Li Yimin: Selective Nanocatalysis of Organic Transformation by Metals: Concepts, Model Systems, and Instruments. Top Catal 2010, 53, 832. <http://dx.doi.org/10.1007/s11244-010-9511-y>
- Motoyama Yukihiro, Kamo Kazuyuki, Yuasa Akihiro, Nagashima Hideo: Catalytic atom-transfer radical cyclization by copper/bipyridine species encapsulated in polysiloxane gel. Chem Commun 2010, 46, 2256. <http://dx.doi.org/10.1039/b923213c>
- Schmaderer Harald, Hilgers Petra, Lechner Robert, König Burkhard: Photooxidation of Benzyl Alcohols with Immobilized Flavins. Adv Synth Catal 2009, 351, 163. <http://dx.doi.org/10.1002/adsc.200800576>
- Jarzembska Katarzyna, Seal Sudipta, Woźniak Krzysztof, Szadkowska Anna, Bieniek Michał, Grela Karol: X-Ray Photoelectron Spectroscopy and Reactivity Studies of a Series of Ruthenium Catalysts. ChemCatChem 2009, 1, 144. <http://dx.doi.org/10.1002/cctc.200900052>
- Yi Wen-Bin, Cai Chun: Perfluoroalkylated-pyridine catalyzed Aldol condensations of aldehydes and ketones in a fluorous biphasic system without fluorous solvent. J FLUORINE CHEM 2009, 130, 484. <http://dx.doi.org/10.1016/j.jfluchem.2009.02.013>
- Alexander S., Udayakumar V., Gayathri V.: Hydrogenation of olefins by polymer-bound palladium(II) Schiff base catalyst. Journal of Molecular Catalysis A 2009, 314, 21. <http://dx.doi.org/10.1016/j.molcata.2009.08.012>
- Zhang Wei: Green chemistry aspects of fluorous techniques—opportunities and challenges for small-scale organic synthesis. Green Chem 2009, 11, 911. <http://dx.doi.org/10.1039/b820740b>
- Zheng Wen-Wei, Hsieh Yi-Han, Chiu Yu-Chung, Cai Sian-Jhu, Cheng Chia-Liang, Chen Chinpiao: Organic functionalization of ultradispersed nanodiamond: synthesis and applications. J Mater Chem 2009, 19, 8432. <http://dx.doi.org/10.1039/b904302k>
- Zhang Dong-Hui, Li Hong-Bin, Li Guo-Dong, Chen Jie-Sheng: Magnetically recyclable Ag-ferrite catalysts: general synthesis and support effects in the epoxidation of styrene. Dalton Trans 2009, 10527. <http://dx.doi.org/10.1039/b915232f>
- Yi Wen-Bin, Cai Chun: Perfluoroalkylated pyridine catalyzed Knoevenagel condensation: An important complement of fluorous catalysis without fluorous solvent. Catal Commun 2008, 9, 1291. <http://dx.doi.org/10.1016/j.catcom.2007.11.020>
- Yi Wen-Bin, Cai Chun: Polymer-supported ytterbium perfluorooctanesulfonate [Yb(OPf)3]: A recyclable catalyst for organic reactions. J FLUORINE CHEM 2008, 129, 524. <http://dx.doi.org/10.1016/j.jfluchem.2008.03.013>
- Lu Norman, Chen Shih-Chieh, Chen Tsung-Chi, Liu Ling-Kang: Palladium-catalyzed Heck reaction under thermomorphic mode. Tetrahetron Lett 2008, 49, 371. <http://dx.doi.org/10.1016/j.tetlet.2007.11.034>
- Motoyama Yukihiro, Abe Motonori, Kamo Kazuyuki, Kosako Yusuke, Nagashima Hideo: Encapsulated molecular catalysts in polysiloxane gels: ruthenium cluster-catalyzed isomerization of alkenes. Chem Commun 2008, 5321. <http://dx.doi.org/10.1039/b809937e>
- Nanocrystalline Copper Oxide(II)-Catalyzed Alkyne-Azide Cycloadditions. Bulletin of the Korean Chemical Society 2008, 29, 1561. <http://dx.doi.org/10.5012/bkcs.2008.29.8.1561>
- Hamamoto Hiromi, Suzuki Yachiyo, Takahashi Hideyo, Ikegami Shiro: A New Solid-Phase Reaction System Utilizing a Temperature- Responsive Catalyst: Oxidative Cyclization with Hydrogen Peroxide. Adv Synth Catal 2007, 349, 2685. <http://dx.doi.org/10.1002/adsc.200700114>
- Clavier Hervé, Grela Karol, Kirschning Andreas, Mauduit Marc, Nolan Steven P.: Nachhaltige Konzepte in der Olefinmetathese. Angew Chem 2007, 119, 6906. <http://dx.doi.org/10.1002/ange.200605099>
- Ng Danny, Yang Zhe, Garcia-Garibay Miguel A., Natarajan Arunkumar: Parallel Syntheses of (+)- and (−)-α-Cuparenone by Radical Combination in Crystalline Solids. Angew Chem 2007, 119, 6605. <http://dx.doi.org/10.1002/ange.200700679>
- Clavier Hervé, Grela Karol, Kirschning Andreas, Mauduit Marc, Nolan Steven P.: Sustainable Concepts in Olefin Metathesis. Angew Chem Int Ed 2007, 46, 6786. <http://dx.doi.org/10.1002/anie.200605099>
- Natarajan Arunkumar, Ng Danny, Yang Zhe, Garcia-Garibay Miguel A.: Parallel Syntheses of (+)- and (−)-α-Cuparenone by Radical Combination in Crystalline Solids. Angew Chem Int Ed 2007, 46, 6485. <http://dx.doi.org/10.1002/anie.200700679>
- Hao Xiuhua, Yoshida Akihiro, Hoshi Nobuto: Recyclable hafnium(IV) bis(perfluorooctanesulfonyl)amide complex for catalytic Friedel–Crafts acylation and Prins reaction in fluorous biphase system. J FLUORINE CHEM 2007, 128, 1396. <http://dx.doi.org/10.1016/j.jfluchem.2007.07.007>
- Durgun Gülay, Aksın Özge, Artok Levent: Pd-loaded NaY zeolite as a highly active catalyst for ligandless Suzuki–Miyaura reactions of aryl halides at low Pd loadings under aerobic conditions. Journal of Molecular Catalysis A 2007, 278, 189. <http://dx.doi.org/10.1016/j.molcata.2007.09.010>
- Hamamoto Hiromi, Suzuki Yachiyo, Takahashi Hideyo, Ikegami Shiro: Direct transformation of benzilic amines to carbonyls using polyacrylamide-bound tungstate under phase-transfer catalysis conditions. Tetrahetron Lett 2007, 48, 4239. <http://dx.doi.org/10.1016/j.tetlet.2007.04.071>
- Hamamoto Hiromi, Kudoh Masahiro, Takahashi Hideyo, Natsugari Hideaki, Ikegami Shiro: Polyacrylamide-based Functional Polymer-immobilized Perruthenate for Aerobic Alcohol Oxidation. Chem Lett 2007, 36, 632. <http://dx.doi.org/10.1246/cl.2007.632>
- Phan Nam T. S., Van Der Sluys Matthew, Jones Christopher W.: On the Nature of the Active Species in Palladium Catalyzed Mizoroki–Heck and Suzuki–Miyaura Couplings – Homogeneous or Heterogeneous Catalysis, A Critical Review. Adv Synth Catal 2006, 348, 609. <http://dx.doi.org/10.1002/adsc.200505473>
- Tse Man Kin, Bhor Santosh, Klawonn Markus, Anilkumar Gopinathan, Jiao Haijun, Döbler Christian, Spannenberg Anke, Mägerlein Wolfgang, Hugl Herbert, Beller Matthias: Ruthenium-Catalyzed Asymmetric Epoxidation of Olefins Using H2O2, Part I: Synthesis of New ChiralN,N,N-Tridentate Pybox and Pyboxazine Ligands and Their Ruthenium Complexes. Chem Eur J 2006, 12, 1855. <http://dx.doi.org/10.1002/chem.200501261>
- Krafft Marie Pierre: Highly fluorinated compounds induce phase separation in, and nanostructuration of liquid media. Possible impact on, and use in chemical reactivity control. J Polym Sci A Polym Chem 2006, 44, 4251. <http://dx.doi.org/10.1002/pola.21508>
- Hao Xiuhua, Yoshida Akihiro, Nishikido Joji: Metal bis(perfluorooctanesulfonyl)amides as highly efficient Lewis acid catalysts for fluorous biphase organic reactions. J FLUORINE CHEM 2006, 127, 193. <http://dx.doi.org/10.1016/j.jfluchem.2005.10.017>
- Hamamoto Hiromi, Kudoh Masahiro, Takahashi Hideyo, Ikegami Shiro: Novel Use of Cross-Linked Poly(N-isopropylacrylamide) Gel for Organic Reactions in Aqueous Media. Org Lett 2006, 8, 4015. <http://dx.doi.org/10.1021/ol061562b>
- Hao Xiuhua, Hoshi Nobuto: Facile and Recyclable Method for the Prins Reaction Using Hafnium(IV) Bis(perfluorooctanesulfonyl)amides in Fluorous Biphase System. Chem Lett 2006, 35, 1102. <http://dx.doi.org/10.1246/cl.2006.1102>
- Dinh Long V., Gladysz J. A.: “Katalysatoren am laufenden Band” - Teflon: eine neue Methode zur Applikation und Wiedergewinnung homogener fluoriger Katalysatoren. Angew Chem 2005, 117, 4164. <http://dx.doi.org/10.1002/ange.200500237>
- Hamamoto Hiromi, Suzuki Yachiyo, Yamada Yoichi M. A., Tabata Hidetsugu, Takahashi Hideyo, Ikegami Shiro: A Recyclable Catalytic System Based on a Temperature-Responsive Catalyst. Angew Chem 2005, 117, 4612. <http://dx.doi.org/10.1002/ange.200500574>
- Astruc Didier, Lu Feng, Aranzaes Jaime Ruiz: Nanopartikel als regenerierbare Katalysatoren: an der Nahtstelle zwischen homogener und heterogener Katalyse. Angew Chem 2005, 117, 8062. <http://dx.doi.org/10.1002/ange.200500766>
- Dinh Long V., Gladysz J. A.: “Catalyst-on-a-Tape”—Teflon: A New Delivery and Recovery Method for Homogeneous Fluorous Catalysts. Angew Chem Int Ed 2005, 44, 4095. <http://dx.doi.org/10.1002/anie.200500237>
- Hamamoto Hiromi, Suzuki Yachiyo, Yamada Yoichi M. A., Tabata Hidetsugu, Takahashi Hideyo, Ikegami Shiro: A Recyclable Catalytic System Based on a Temperature-Responsive Catalyst. Angew Chem Int Ed 2005, 44, 4536. <http://dx.doi.org/10.1002/anie.200500574>
- Astruc Didier, Lu Feng, Aranzaes Jaime Ruiz: Nanoparticles as Recyclable Catalysts: The Frontier between Homogeneous and Heterogeneous Catalysis. Angew Chem Int Ed 2005, 44, 7852. <http://dx.doi.org/10.1002/anie.200500766>
- Tzschucke Carl Christoph, Andrushko Vasyl, Bannwarth Willi: Assessment of the Reusability of Pd Complexes Supported on Fluorous Silica Gel as Catalysts for Suzuki Couplings. Eur J Org Chem 2005, 2005, 5248. <http://dx.doi.org/10.1002/ejoc.200500281>
- Anilkumar Gopinathan, Bhor Santosh, Tse Man Kin, Klawonn Markus, Bitterlich Bianca, Beller Matthias: Synthesis of a novel class of chiral N,N,N-tridentate pyridinebisimidazoline ligands and their application in Ru-catalyzed asymmetric epoxidations. Tet Asymm 2005, 16, 3536. <http://dx.doi.org/10.1016/j.tetasy.2005.08.060>
- Bhor Santosh, Anilkumar Gopinathan, Tse Man Kin, Klawonn Markus, Döbler Christian, Bitterlich Bianca, Grotevendt Anne, Beller Matthias: Synthesis of a New Chiral N,N,N-Tridentate Pyridinebisimidazoline Ligand Library and Its Application in Ru-Catalyzed Asymmetric Epoxidation. Org Lett 2005, 7, 3393. <http://dx.doi.org/10.1021/ol050821e>
- Tzschucke Carl Christoph, Bannwarth Willi: Fluorous-Silica-Supported Perfluoro-Tagged Palladium Complexes CatalyzeSuzuki Couplings in Water. HCA 2004, 87, 2882. <http://dx.doi.org/10.1002/hlca.200490260>
- Hao Xiuhua, Yamazaki Osamu, Yoshida Akihiro, Nishikido Joji: Tin(IV) bis(perfluoroalkanesulfonyl)amide complex as a highly selective Lewis acid catalyst for Baeyer–Villiger oxidation using hydrogen peroxide in a fluorous recyclable phase. Tetrahetron Lett 2003, 44, 4977. <http://dx.doi.org/10.1016/S0040-4039(03)01185-7>
- Rocaboy Christian, Gladysz J.A: Syntheses, oxidations, and palladium complexes of fluorous dialkyl sulfides: new precursors to highly active catalysts for the Suzuki coupling. Tetrahedron 2002, 58, 4007. <http://dx.doi.org/10.1016/S0040-4020(02)00275-2>
- Rocaboy Christian, Gladysz J. A.: Highly Active Thermomorphic Fluorous Palladacycle Catalyst Precursors for the Heck Reaction; Evidence for a Palladium Nanoparticle Pathway. Org Lett 2002, 4, 1993. <http://dx.doi.org/10.1021/ol025790r>
- Casas Jesús, Nájera Carmen, Sansano José M., Saá José M.: BINOLAM, a Recoverable Chiral Ligand for Bifunctional Enantioselective Catalysis: The Asymmetric Synthesis of Cyanohydrins†. Org Lett 2002, 4, 2589. <http://dx.doi.org/10.1021/ol0262338>