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Annulation

December 13, 2023

Not to be confused with Annulment.

In organic chemistry annulation (from the Latin anellus for "little ring"; occasionally annelation) is a chemical reaction in which a new ring is constructed on a molecule.[1]

Examples are the Robinson annulation, Danheiser annulation and certain cycloadditions. Annular molecules are constructed from side-on condensed cyclic segments, for example helicenes and acenes. In transannulation a bicyclic molecule is created by intramolecular carbon-carbon bond formation in a large monocyclic ring. An example is the samarium(II) iodide induced ketone - alkene cyclization of 5-methylenecyclooctanone which proceeds through a ketyl intermediate:[2]

Benzannulation edit

The term benzannulated compounds refers to derivatives of cyclic compounds (usually aromatic) which are fused to a benzene ring. Examples are listed in the table below:

In contemporary chemical literature, the term benzannulation also means "construction of benzene rings from acyclic precursors".[3]

 
Protonation of Verkade base induces a transannular bonding, giving an atrane.[4]

Transannular interaction edit

A transannular interaction in chemistry is any chemical interaction (favorable or nonfavorable) between different non-bonding molecular groups in a large ring or macrocycle.[5] See for example atranes.

References edit

  1. ^ IUPAC, Compendium of Chemical Terminology, 2nd ed. (the "Gold Book") (1997). Online corrected version: (2006–) "annulation". doi:10.1351/goldbook.A00367IUPAC, Compendium of Chemical Terminology, 2nd ed. (the "Gold Book") (1997). Online corrected version: (2006–) "annelation". doi:10.1351/goldbook.A00365.html
  2. ^ Construction of Bicyclic Ring Systems via a Transannular SmI2-Mediated Ketone-Olefin Cyclization StrategyGary A. Molander, Barbara Czakó, and Michael Rheam J. Org. Chem.; 2007; 72(5) pp 1755 - 1764; (Article) doi:10.1021/jo062292d
  3. ^ Swami, Bhawna; Yadav, Deepak; Menon, Rajeev S. (January 2022). "Benzannulation Reactions: A Case for Perspective Change From Arene Decoration to Arene Construction". The Chemical Record. 22 (1): e202100249. doi:10.1002/tcr.202100249. ISSN 1527-8999. PMID 34796605. S2CID 244403005.
  4. ^ Verkade, John G.; Urgaonkar, Sameer; Verkade, John G.; Urgaonkar, Sameer (2012). "Proazaphosphatrane". Encyclopedia of Reagents for Organic Synthesis. doi:10.1002/047084289X.rn00702.pub2. ISBN 978-0471936237.
  5. ^ Experimental evidence in support of transannular interactions in diketones Kata Mlinaric-Majerski, Marijana Vinkovic, Danko Škare, Alan P. Marchand Arkivoc DS-339E 2002 Online Article 2006-05-04 at the Wayback Machine

December 13, 2023
annulation, confused, with, annulment, organic, chemistry, annulation, from, latin, anellus, little, ring, occasionally, annelation, chemical, reaction, which, ring, constructed, molecule, examples, robinson, annulation, danheiser, annulation, certain, cycload. Not to be confused with Annulment In organic chemistry annulation from the Latin anellus for little ring occasionally annelation is a chemical reaction in which a new ring is constructed on a molecule 1 Examples are the Robinson annulation Danheiser annulation and certain cycloadditions Annular molecules are constructed from side on condensed cyclic segments for example helicenes and acenes In transannulation a bicyclic molecule is created by intramolecular carbon carbon bond formation in a large monocyclic ring An example is the samarium II iodide induced ketone alkene cyclization of 5 methylenecyclooctanone which proceeds through a ketyl intermediate 2 Benzannulation editThe term benzannulated compounds refers to derivatives of cyclic compounds usually aromatic which are fused to a benzene ring Examples are listed in the table below Benzannulated derivative Source of cyclic compoundBenzopyrene PyreneQuinoline PyridineIsoquinolineChromene PyranIsochromeneIndole PyrroleIsoindoleBenzofuran FuranIsobenzofuranBenzimidazole ImidazoleIn contemporary chemical literature the term benzannulation also means construction of benzene rings from acyclic precursors 3 nbsp Protonation of Verkade base induces a transannular bonding giving an atrane 4 Transannular interaction editA transannular interaction in chemistry is any chemical interaction favorable or nonfavorable between different non bonding molecular groups in a large ring or macrocycle 5 See for example atranes References edit IUPAC Compendium of Chemical Terminology 2nd ed the Gold Book 1997 Online corrected version 2006 annulation doi 10 1351 goldbook A00367IUPAC Compendium of Chemical Terminology 2nd ed the Gold Book 1997 Online corrected version 2006 annelation doi 10 1351 goldbook A00365 html Construction of Bicyclic Ring Systems via a Transannular SmI2 Mediated Ketone Olefin Cyclization StrategyGary A Molander Barbara Czako and Michael Rheam J Org Chem 2007 72 5 pp 1755 1764 Article doi 10 1021 jo062292d Swami Bhawna Yadav Deepak Menon Rajeev S January 2022 Benzannulation Reactions A Case for Perspective Change From Arene Decoration to Arene Construction The Chemical Record 22 1 e202100249 doi 10 1002 tcr 202100249 ISSN 1527 8999 PMID 34796605 S2CID 244403005 Verkade John G Urgaonkar Sameer Verkade John G Urgaonkar Sameer 2012 Proazaphosphatrane Encyclopedia of Reagents for Organic Synthesis doi 10 1002 047084289X rn00702 pub2 ISBN 978 0471936237 Experimental evidence in support of transannular interactions in diketones Kata Mlinaric Majerski Marijana Vinkovic Danko Skare Alan P Marchand Arkivoc DS 339E 2002 Online Article Archived 2006 05 04 at the Wayback Machine Retrieved from https en wikipedia org w index php title Annulation amp oldid 1141651436, wikipedia, wiki, book, books, library,

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