• Later on, Prins reaction emerged as a powerful C-O and C-C bond forming technique in the synthesis of various molecules in organic synthesis. (wikipedia.org)
  • Since our lab recently reported a synthesis of the natural product aristoquinoline [7] , we viewed the halichonic acids as ideal targets to extend the scope of our synthetic methodology. (beilstein-journals.org)
  • This prompted us to investigate a biomimetic synthesis in which the halichonic acids could be prepared from a common imine intermediate via divergent intramolecular aza-Prins cyclizations [8] . (beilstein-journals.org)
  • The Prins cyclization of styrene (SE) with paraformaldehyde (PFCHO) was conducted with mesoporous ZnAlMCM-41 catalysts for the synthesis of 4-phenyl-1,3-dioxane (4-PDO) using a liquid phase heterogeneous catalytic method. (iith.ac.in)
  • Since ZnAlMCM-41(75) has higher catalytic activity than other solid acid catalysts, washed ZnAlMCM-41(75)/W-ZnAlMCM-41(75) was prepared using an efficient chemical treatment method and used with various reaction parameters to find an optimal parameter for the highly selective synthesis of 4-PDO. (iith.ac.in)
  • W-ZnAlMCM-41(75) was also used in the Prins cyclization of olefins with PFCHO and formalin (FN, 37% aqueous solution of formaldehyde (FCHO)) under different reaction conditions to obtain 1,3-dioxanes, which are widely used as solvents or intermediates in organic synthesis. (iith.ac.in)
  • Also, camphor sulfonic acid (CSA) is achieving enormous significance in organic synthesis, as this catalyst is used in the synthesis of chromans, ligands, and pseudo glycosides, as an auxiliary and in some polymerization reactions [8]. (lupinepublishers.com)
  • So far, to the best of our knowledge, there is no report available on the use of camphor sulfonic acid as an organ catalyst for the synthesis of highly substituted Piperidines. (lupinepublishers.com)
  • 2017 ) Total Synthesis of (+)-Lophirone H and Its Pentamethyl Ether Utilizing an Oxonium-Prins Cyclization. (academictree.org)
  • List, B. Highly Acidic BINOL-Derived Phosphoramidimidates and their Application in the Brønsted Acid Catalyzed Synthesis of a α-Tocopherol. (mpg.de)
  • The key intramolecular aza-Prins reaction forms the characteristic 3-azabicyclo[3.3.1]nonane ring system of halichonic acid along with the lactonized form of halichonic acid B in an 8:1 ratio. (beilstein-journals.org)
  • These findings led to investigations of intramolecular Aza-Prins reactions that must invoke the N -sulfonyliminium ion to cyclize. (usm.edu)
  • The Prins reaction is an organic reaction consisting of an electrophilic addition of an aldehyde or ketone to an alkene or alkyne followed by capture of a nucleophile or elimination of an H+ ion. (wikipedia.org)
  • Investigations into electrophilic cyclization looked to overcome this phenomenon by introducing a known chiral center α to an amine where a protecting group, sulfonamide, is added to increase the torsional and allylic strain in the molecules. (usm.edu)
  • Pictet-Spengler cyclizations were thoroughly scouted for Lewis acids that would coordinate to an aldehyde, enabling the sulfonamide to attack the electrophilic carbonyl and initiate a cyclization. (usm.edu)
  • The first one is the addition of polyhalogen compound to olefins and the second reaction is the acid catalyzed addition of aldehydes to olefin compounds. (wikipedia.org)
  • Recently, our group synthesized 1,5-benzodiazepine, α-hydroxy and α-amino phosphonates using camphor sulfonic acid as organ catalyst [7]. (lupinepublishers.com)
  • Originally discovered by Sodeoka 25 years ago, they readily form reactive chiral Pd enolates upon deprotonation of b-dicarbonyl compounds and simultaneously, a Brønsted acid liberated from the catalyst activates the electrophile. (uni-leipzig.de)
  • The original reactants employed by Dutch chemist Hendrik Jacobus Prins [de] in his 1919 publication were styrene (scheme 2), pinene, camphene, eugenol, isosafrole and anethole. (wikipedia.org)
  • List, B. Catalytic Asymmetric Vinylogous Prins Cyclization: A Highly Diastereo- and Enantioselective Entry to Tetrahydrofurans. (mpg.de)
  • 2020 ) meta-Selective C-H functionalisation of aryl boronic acids directed by a MIDA-derived boronate ester Chemical Science . (academictree.org)
  • Hendrik Jacobus Prins discovered two new organic reactions during his doctoral research in the year of 1911-1912. (wikipedia.org)
  • Many variations of the Prins reaction exist because it lends itself easily to cyclization reactions and because it is possible to capture the oxo-carbenium ion with a large array of nucleophiles. (wikipedia.org)
  • This strategy demonstrated five component reactions of two equivalents of aldehydes, two equivalents of anilines and (3-keto esters in ethanol using 10 mol% of camphor sulfonic acid at reflux. (lupinepublishers.com)
  • The halo-Prins reaction is one such modification with replacement of protic acids and water by lewis acids such as stannic chloride and boron tribromide. (wikipedia.org)
  • With lewis acid stannic chloride the oxonium ion is activated and the pinacol rearrangement of the resulting Prins intermediate results in ring contraction and referral of the positive charge to the TIPS ether which eventually forms an aldehyde group in the final product as a mixture of cis and trans isomers with modest diastereoselectivity. (wikipedia.org)
  • Research, herein, does an expansive initiator screen and identifies Lewis acids to propose a mechanism for inducing cyclization. (usm.edu)
  • List, B. Asymmetric Counteranion-Directed Lewis Acid Organocatalysis for the Scalable Cyanosilylation of Aldehydes. (mpg.de)
  • List, B. Asymmetric Lewis Acid Organocatalysis of the Diels-Alder Reaction by a Silylated C-H Acid. (mpg.de)
  • The carbonyl reactant (2) is protonated by a protic acid and for the resulting oxonium ion 3 two resonance structures can be drawn. (wikipedia.org)
  • Dependent on the sulfoxide reactivity to initiate the reaction, the Pummerer cyclization has been looked over due to the lack of reactivity of unsubstituted alkenes. (usm.edu)
  • 2019 ) Reversibility and reactivity in an acid catalyzed cyclocondensation to give furanochromanes - a reaction at the 'oxonium-Prins' '-quinone methide cycloaddition' mechanistic nexus. (academictree.org)
  • Based upon their exceptional reactivity as cooperative Brønsted acid-base catalysts, chiral diphosphane Pd-aqua complexes have successfully been utilized in a broad range of asymmetric transformations. (uni-leipzig.de)
  • List, B. A General Catalytic Asymmetric Prins Cyclization. (mpg.de)
  • A cooperative catalytic process through Palladium and Brønsted acid activation has been developed for the conjugate addition of cyclic ß -keto esters 2 to azoalkenes 1 directly followed by hemiaminal formation upon cyclization. (uni-leipzig.de)
  • We report herein the catalytic asymmetric cyclization of 1-aryl terpenols to afford enantiomerically highly enriched cis-tetrahydrocannabinoid scaffolds in a single step. (uni-leipzig.de)
  • Based on the nature of catalysts used under different reaction conditions, a reasonable plausible reaction mechanism for the Prins cyclization of SE with PFCHO is proposed. (iith.ac.in)
  • For a comparison study, the Prins cyclization reaction was also conducted over different nanoporous catalysts,e.g.mesoporous solid acid catalysts, AlMCM-41(21) and ZnMCM-41(21), and microporous catalysts, USY, Hβ, HZSM-5, and H-mordenite. (iith.ac.in)
  • This transformation was enabled by utilizing chiral Pd-aqua complexes as combined Brønsted acid-base catalysts. (uni-leipzig.de)
  • We report herein an asymmetric cooperative process for the enantioselective 1,6-addition of β-ketoesters to in situ generated para-quinone methides with chiral Pd−aqua complexes as mixed Brønsted acid−base catalysts. (uni-leipzig.de)
  • Optical rotation measurements confirmed that these synthetic compounds were in fact the enantiomers of the natural products, establishing both the relative and absolute configurations of the halichonic acids. (beilstein-journals.org)
  • List, B. Phosphoric Acid Based Heterodimers in Asymmetric Catalysis. (mpg.de)
  • When water is replaced by acetic acid the corresponding esters are formed. (wikipedia.org)
  • Our group was particularly interested in the structure of halichonic acid ((+)- 1 ), which shares the same bridged bicyclic ring system found in many of the Aristotelia alkaloids [6] . (beilstein-journals.org)
  • List, B. The Activation of Carboxylic Acids Via Self-Assembly Asymmetric Organocatalysis: A Combined Experimental and Computational Investigation. (mpg.de)
  • We have developed a novel and effective process for the direct generation of this structural motif in a (3+2)-cycloaddition of thioketones and acetylenedicarboxylic acid. (uni-leipzig.de)
  • This amino acid natural product features a rigid 3-azabicyclo[3.3.1]nonane ring system containing four stereogenic centers within the piperidine ring. (beilstein-journals.org)
  • The cyclization of certain allyl pulegones in scheme 7 with titanium tetrachloride in dichloromethane at −78 °C gives access to the decalin skeleton with the hydroxyl group and chlorine group predominantly in cis configuration (91% cis). (wikipedia.org)
  • METHODS: Serum 25-hydroxyvitamin D (25(OH)D) levels were assessed in 68 MM patients at a single institution in Japan, analyzing their association with clinical status, laboratory parameters including procollagen type 1 N-propeptide (P1NP) and tartrate-resistant acid phosphatase 5b (TRACP-5b), health-related quality of life (HR-QOL) scores, and overall survival. (bvsalud.org)