• This step results from an intramolecular cyclization reaction in which the carbonyl (C=O) group that was a part of the original isocyanate group (-N=C=O), is effectively extracted to yield perimidone and the amine corresponding to the original isocyanate species. (cdc.gov)
  • Hamme, A. T. II "Spiroisoxazoline Synthesis via Intramolecular Cyclization/Methylation" Synthesis 2006 , 3815-3818. (jsums.edu)
  • Allenyl alcohols underwent an intramolecular cyclization to 2,5-dihydrofurans in the presence of Fetizon's reagent and this process was then optimized using silver fluoride. (umsystem.edu)
  • The obtained (Z)-2-bromovinyl phenyl ethers subsequently proceeded by intramolecular cyclization to afford 2-substituted benzo[b]furans in good yields through palladium-catalyzed direct C-H bond functionalizations. (unboundmedicine.com)
  • This tandem cyclization consists of α,β-unsaturated aldehyde formation, intramolecular aldol reaction, six-membered lactamization, azide reduction, and seven-membered lactamization. (tokushima-u.ac.jp)
  • Radical cyclization reactions are organic chemical transformations that yield cyclic products through radical intermediates. (wikipedia.org)
  • Radical cyclization reactions produce mono- or polycyclic products through the action of radical intermediates. (wikipedia.org)
  • Disadvantages: the relative rates of the various stages of radical cyclization reactions (and any side reactions) must be carefully controlled so that cyclization and trapping of the cyclized radical is favored. (wikipedia.org)
  • Side reactions are sometimes a problem, and cyclization is especially slow for small and large rings (although macrocyclizations, which resemble intermolecular radical reactions, are often high yielding). (wikipedia.org)
  • Cyclization of the homologous 6-heptenyl radical is still selective, but is much slower-as a result, competitive side reactions are an important problem when these intermediates are involved. (wikipedia.org)
  • 2) Cyclization reactions of vinyl, aryl, and acyl radicals are also known. (wikipedia.org)
  • On-line HPLC-ion spray mass spectrometry was more practical and useful than conventional HPLC alone for characterizing the products of these cyclization reactions. (elsevierpure.com)
  • In the course of pursuing a Nazarov cyclization of allenyl vinyl ketones (AVK), we discovered multiple new reactions. (umsystem.edu)
  • Pelkey, E.T. Preparation of Dibenzo[e,g]isoindol-1-ones via Scholl-Type Oxidative Cyclization Reactions. (hws.edu)
  • In this chapter, we review a selection of examples of catalytic tandem reactions triggered by the introduction of a carbonyl function either formed by oxidation of alcohols, hydroformylation, isomerisation or carbonylation. (eurekaselect.com)
  • Reported here is a Pt‐Au heterobimetallic catalyst system for the synthesis of a family of multi‐heteroaromatic structures through tandem cyclization/C−X coupling reaction. (uea.ac.uk)
  • Pelkey, E.T. Investigating the stereochemical outcome of a tandem cyclization-coupling reaction leading to a 3-arylmethylideneisobenzofuran-1-one. (hws.edu)
  • Hopefully you will find something of interest 🙂 Continuous flow synthesis of menthol via tandem cyclisation-hydrogenation of citronellal catalysed by scrap catalytic converters. (cosmic-etn.eu)
  • The stereochemical outcome in this tandem cyclization is controlled by the stereocenter at the C14 position. (tokushima-u.ac.jp)
  • In Chapter 3, we used sequential catalysis-PPh3-catalyzed nucleophilic addition followed by Pd(0)-catalyzed Heck cyclization-to construct complex functionalized alkylidene phthalans rapidly, in high yields, and with good stereoselectivities (E/Z ratios of up to 1:22). (escholarship.org)
  • 5-hexenyl radicals are the most synthetically useful intermediates for radical cyclizations, because cyclization is extremely rapid and exo selective. (wikipedia.org)
  • Novel synthetic methodologies for the synthesis of substituted phenanthridines and oxindoles utilizing tandem cyclizations of β-keto radicals were developed. (purdue.edu)
  • Cyclopropanols readily undergo single-electron oxidation and ring opening to give β-keto radicals which underwent cyclization with biaryl isonitriles and acrylamides followed by homolytic aromatic substitution to give ketoalkylated phenanthridines and oxindoles. (purdue.edu)
  • A general method for the synthesis of a series of previously unknown N -(heteroaryl)- and N -(aryl)aminotetrazoles through the tandem electrocyclization/hydrolysis of azidohydrazones was accomplished. (hse.ru)
  • One-Pot Synthesis of 1,2-Disubstituted 4-, 5-, 6-, and 7-Azaindoles from Amino-o-halopyridines via N-Arylation/Sonogashira/Cyclization Reaction. (acs.org)
  • The synthesis consists of a tin-mediated tandem radical cyclization of appropriate precursors to form 2,3-disubstituted dihydroindoles, which in turn are oxidized to yield the corresponding 2-arylindoles. (uni-regensburg.de)
  • They usually proceed in three basic steps: selective radical generation, radical cyclization, and conversion of the cyclized radical to product. (wikipedia.org)
  • The radical cyclization step usually involves the attack of a radical on a multiple bond. (wikipedia.org)
  • Three conditions must be met for an efficient radical cyclization to take place: A method must be available to generate a radical selectively on the substrate. (wikipedia.org)
  • Radical cyclization must be faster than trapping of the initially formed radical. (wikipedia.org)
  • Although the exo radical is less thermodynamically stable than the endo radical, the more rapid exo cyclization is rationalized by better orbital overlap in the chair-like exo transition state (see below). (wikipedia.org)
  • Stabilizing the initially formed radical with electron-withdrawing groups provides access to more stable 6-endo cyclization products preferentially. (wikipedia.org)
  • However, low concentrations of a radical scavenger establish thermodynamic control and provide access to 6-endo products-not via 6-endo cyclization, but by 5-exo cyclization followed by 3-exo closure and subsequent fragmentation (Dowd-Beckwith rearrangement). (wikipedia.org)
  • In many cases, exo cyclization is favored over endo cyclization (macrocyclizations constitute the major exception to this rule). (wikipedia.org)
  • Au‐catalyzed 6‐endo‐cyclization takes place as the first fast step. (uea.ac.uk)
  • The key feature of this total synthesis is a one-pot construction of the pentacyclic skeleton containing an azabicyclo[3.3.1]nonane core by tandem cyclization from an indole derivative having all carbon side chains and functional groups. (tokushima-u.ac.jp)
  • We have recently shown this in the stereoselective total synthesis of the antiviral sesquiterpene (+)-schisanwilsonene by a cyclization/1,5-acetoxy migration/intermolecular cyclopropanation. (unboundmedicine.com)
  • In a practical and simple synthesis of 2,5-disubstituted oxazoles via an iodine-catalyzed tandem oxidative cyclization, a wide range of common commercial aromatic aldehydes can be used as reaction substrates, which displayed excellent functional group compatibility. (organic-chemistry.org)
  • Tandem Pummerer/Mannich cyclization cascade of alpha-sulfinylamides as a method to prepare aza-heterocycles. (ncats.io)
  • A small aliquot of impinger solution (0.5 ml) is mixed with an equal volume of formic acid (a catalyst for cyclization). (cdc.gov)
  • EN] A bifunctional metal organic framework catalyst containing palladium and copper(II) benzene- 1,3,5-tricarboxylate - MOF-Cu(BTC)-[Pd] - has been prepared. (upv.es)
  • In addition to the desired cyclic peptide, the peptide byproducts observed following the cyclization using BOP (benzotriazol-1-yl-oxy- tris(dimethylamino)phosphonium hexafluorophosphate) were the linear peptide, the cyclic dimeric peptide and the linear peptide resulting from aspartimide rearrangement. (elsevierpure.com)
  • Tandem Thermal Claisen-Cope Rearrangements of Coumarate Derivatives. (nsmsi.ir)
  • 3) Cyclization can involve heteroatom-containing multiple bonds such as nitriles, oximes, and carbonyls. (wikipedia.org)
  • A novel method has been discovered to generate C-S bonds in tandem with C-C bond formation. (uwaterloo.ca)
  • Rapid Construction of an Imidazo[4,5-b]pyridine Skeleton from 2-Chloro-3-nitropyridine via Tandem Reaction in H2O-IPA Medium. (acs.org)
  • Two-directional synthesis was used to furnish the cyclisation precursor 2, as in each of the subsequent steps towards the natural product. (nottingham.ac.uk)
  • It is important to note that the transformation of phenols with bromoalkynes into benzo[b]furans could be carried out in one pot with a simple and efficient tandem procedure. (unboundmedicine.com)
  • The cyclization of a linear dynorphin A (Dyn A) analogue to give the lactam derivative cyclo[D-Asp 2 ,Dap 5 ]Dyn A(1-13)NH 2 (where Dap = α,β-diaminopropionic acid) was studied to evaluate the usefulness of different coupling reagents for side chain to side chain lactam formation. (elsevierpure.com)
  • A tandem cyclisation stablished the entire core of the structure in a single transformation as well as the required 2,5-anti stereochemistry. (nottingham.ac.uk)
  • Under conditions of kinetic control, 5-exo cyclization takes place preferentially. (wikipedia.org)
  • Recently, significant advances have taken place in the use of SmI 2 for the synthesis of nitrogen heterocycles, enabled in large part by the unique combination of high reducing power of this reagent (E 1/2 of up to −2.8 V) with excellent chemoselectivity of the reductive umpolung cyclizations mediated by SmI 2 . (mdpi.com)
  • In this synthesis, the cyclization/1,5-acetoxy migration is faster than the alternative 1,2-acyloxy migration that would result in racemization. (unboundmedicine.com)