Racemic BINOL can also be produced using iron(III) chloride as an oxidant. The mechanism involves complexation of iron(III) into the hydroxyl, followed by a radical coupling reaction of the naphthol rings initiated by iron(III) reducing into iron(II).
Optically active BINOL can also be obtained from racemic BINOL by optical resolution. In one method, the alkaloid N-benzylcinchonidinium chloride forms a crystalline inclusion compound. The inclusion compound of the (S)-enantiomer is soluble in acetonitrile but that of the (R)-enantiomer is not.[3] In another method BINOL is esterified with pentanoyl chloride. The enzyme cholesterolesterasehydrolyses the (S)-diester but not the (R)-diester.[3] The (R)-dipentanoate is hydrolysed in a second step with sodium methoxide.[4] The third method employs HPLC with chiral stationary phases.[5]
Aside from the starting materials derived directly from the chiral pool, (R)- and (S)-BINOL in high enantiopurity (>99% enantiomeric excess) are two of the most inexpensive sources of chirality for organic synthesis, costing less than US$0.60 per gram when purchased in bulk from chemical suppliers.[7] As a consequence, it serves as an important starting material for other sources of chirality for stereoselective synthesis, both stoichiometric and substoichiometric (catalytic).
Many important chiral ligands are constructed from the binaphthyl scaffold and ultimately derived from BINOL as a starting material, BINAP being one of the most well known and important.
The compound aluminium lithium bis(binaphthoxide) (ALB) is prepared by reaction of BINOL with lithium aluminium hydride.[8] In a different stoichiometric ratio (1:1 BINOL/LiAlH4 instead of 2:1), the chiral reducing agent BINAL (lithium dihydrido(binaphthoxy)aluminate) is produced.[9]
^Brussee, J.; Jansen, A. C. A. (1983). "A highly stereoselective synthesis of S-(−)-[1,1′-binaphthalene]-2,2′-diol". Tetrahedron Letters. 24 (31): 3261–3262. doi:10.1016/S0040-4039(00)88151-4.
^ ab"RESOLUTION OF 1,1'-BI-2-NAPHTHOL" 2012-07-16 at the Wayback Machine, Dongwei Cai, David L. Hughes, Thomas R. Verhoeven, and Paul J. Reider, in Organic Syntheses Coll. Vol. 10, p.93; Vol. 76, p.1
^"(S)-(−)- and (R)-(+)-1,1′-bi-2-naphthol" 2005-04-18 at the Wayback Machine, Romas J. Kazlauskas in Organic Syntheses, Coll. Vol. 9, p.77; Vol. 70, p.60
^Landek, G.; Vinković, M.; Kontrec, D.; Vinković, V. (2006). "Influence of mobile phase and temperature on separation of 1,1′-binaphthyl-2,2′-diol enantiomers with brush type chiral stationary phases derived from L-leucine". Chromatographia. 64 (7–8): 469–473. doi:10.1365/s10337-006-0041-5. S2CID 95785346.
^Parmar, Dixit; Sugiono, Erli; Raja, Sadiya; Rueping, Magnus (2014). "Complete Field Guide to Asymmetric BINOL-Phosphate Derived Brønsted Acid and Metal Catalysis: History and Classification by Mode of Activation; Brønsted Acidity, Hydrogen Bonding, Ion Pairing, and Metal Phosphates". Chemical Reviews. 114 (18): 9047–9153. doi:10.1021/cr5001496. PMID 25203602.
^Yang, Jin-Fei; Wang, Rong-Hua; Wang, Yin-Xia; Yao, Wei-Wei; Liu, Qi-Sheng; Ye, Mengchun (2016-10-11). "Ligand-Accelerated Direct C−H Arylation of BINOL: A Rapid One-Step Synthesis of Racemic 3,3′-Diaryl BINOLs". Angewandte Chemie International Edition. 55 (45): 14116–14120. doi:10.1002/anie.201607893. ISSN 1433-7851. PMID 27726256.
^A practical large-scale synthesis of enantiomerically pure 3-[bis(methoxycarbonyl)methyl]cyclohexanone via catalytic asymmetric Michael reactionTetrahedron, Volume 58, Issue 13, 25 March 2002, Pages 2585–2588 Youjun Xu, Ken Ohori, Takashi Ohshima, Masakatsu Shibasaki doi:10.1016/S0040-4020(02)00141-2
^Gopalan, Aravamudan S.; Jacobs, Hollie K. (2001-04-15), "Lithium Aluminum Hydride-2,2′-Dihydroxy-1,1′-binaphthyl", Encyclopedia of Reagents for Organic Synthesis, John Wiley & Sons, Ltd, doi:10.1002/047084289x.rl041, ISBN0471936235
April 11, 2024
naphthol, naphthol, binol, organic, compound, that, often, used, ligand, transition, metal, catalysed, asymmetric, synthesis, binol, axial, chirality, enantiomers, readily, separated, stable, toward, racemisation, specific, rotation, enantiomers, with, enantio. 1 1 Bi 2 naphthol BINOL is an organic compound that is often used as a ligand for transition metal catalysed asymmetric synthesis BINOL has axial chirality and the two enantiomers can be readily separated and are stable toward racemisation The specific rotation of the two enantiomers is 35 5 c 1 in THF with the R enantiomer being the dextrorotary one BINOL is a precursor for another chiral ligand called BINAP The volumetric mass density of the two enantiomers is 0 62 g cm 3 citation needed 1 1 Bi 2 naphthol Skeletal formula of R BINOL Skeletal formula of S BINOLBall and stick model of R BINOL R BINOL Ball and stick model of S BINOL S BINOLNamesPreferred IUPAC name 1 1 Binaphthalene 2 2 diolOther names 1 1 Bi 2 naphthol1 1 BinaphtholBINOLBinolIdentifiersCAS Number 602 09 5 R S 18531 94 7 R 18531 99 2 S 3D model JSmol R S Interactive imageChEMBL ChEMBL138718 YChemSpider 11269 YECHA InfoCard 100 009 104PubChem CID 11762UNII 25AB254328 R S YM6IDZ128WT R Y54OT5RRV4C S YCompTox Dashboard EPA DTXSID9060526InChI InChI 1S C20H14O2 c21 17 11 9 13 5 1 3 7 15 13 19 17 20 16 8 4 2 6 14 16 10 12 18 20 22 h1 12 21 22H YKey PPTXVXKCQZKFBN UHFFFAOYSA N YInChI 1 C20H14O2 c21 17 11 9 13 5 1 3 7 15 13 19 17 20 16 8 4 2 6 14 16 10 12 18 20 22 h1 12 21 22HKey PPTXVXKCQZKFBN UHFFFAOYAXSMILES R S C1 CC C2C C1 C CC C2C3 C C CC4 CC CC C43 O OPropertiesChemical formula C 20H 14O 2Molar mass 286 32 g molMelting point 205 to 211 C 401 to 412 F 478 to 484 K 1 Except where otherwise noted data are given for materials in their standard state at 25 C 77 F 100 kPa Y verify what is Y N Infobox references Contents 1 Preparation 2 BINOL derivatives 3 See also 4 ReferencesPreparation editThe organic synthesis of BINOL is not a challenge as such but the preparation of the individual enantiomers is S BINOL can be prepared directly from an asymmetric oxidative coupling of 2 naphthol with copper II chloride The chiral ligand in this reaction is S amphetamine 2 nbsp Racemic BINOL can also be produced using iron III chloride as an oxidant The mechanism involves complexation of iron III into the hydroxyl followed by a radical coupling reaction of the naphthol rings initiated by iron III reducing into iron II Optically active BINOL can also be obtained from racemic BINOL by optical resolution In one method the alkaloid N benzylcinchonidinium chloride forms a crystalline inclusion compound The inclusion compound of the S enantiomer is soluble in acetonitrile but that of the R enantiomer is not 3 In another method BINOL is esterified with pentanoyl chloride The enzyme cholesterol esterase hydrolyses the S diester but not the R diester 3 The R dipentanoate is hydrolysed in a second step with sodium methoxide 4 The third method employs HPLC with chiral stationary phases 5 BINOL derivatives edit nbsp Structure of a chiral phosphoric acid derived from BINOL 6 Aside from the starting materials derived directly from the chiral pool R and S BINOL in high enantiopurity gt 99 enantiomeric excess are two of the most inexpensive sources of chirality for organic synthesis costing less than US 0 60 per gram when purchased in bulk from chemical suppliers 7 As a consequence it serves as an important starting material for other sources of chirality for stereoselective synthesis both stoichiometric and substoichiometric catalytic Many important chiral ligands are constructed from the binaphthyl scaffold and ultimately derived from BINOL as a starting material BINAP being one of the most well known and important The compound aluminium lithium bis binaphthoxide ALB is prepared by reaction of BINOL with lithium aluminium hydride 8 In a different stoichiometric ratio 1 1 BINOL LiAlH4 instead of 2 1 the chiral reducing agent BINAL lithium dihydrido binaphthoxy aluminate is produced 9 nbsp It has been employed in an asymmetric Michael reaction with cyclohexenone and dimethyl malonate nbsp See also editShibasaki catalystsReferences edit Datasheet chemexper com Brussee J Jansen A C A 1983 A highly stereoselective synthesis of S 1 1 binaphthalene 2 2 diol Tetrahedron Letters 24 31 3261 3262 doi 10 1016 S0040 4039 00 88151 4 a b RESOLUTION OF 1 1 BI 2 NAPHTHOL Archived 2012 07 16 at the Wayback Machine Dongwei Cai David L Hughes Thomas R Verhoeven and Paul J Reider in Organic Syntheses Coll Vol 10 p 93 Vol 76 p 1 S and R 1 1 bi 2 naphthol Archived 2005 04 18 at the Wayback Machine Romas J Kazlauskas in Organic Syntheses Coll Vol 9 p 77 Vol 70 p 60 Landek G Vinkovic M Kontrec D Vinkovic V 2006 Influence of mobile phase and temperature on separation of 1 1 binaphthyl 2 2 diol enantiomers with brush type chiral stationary phases derived from L leucine Chromatographia 64 7 8 469 473 doi 10 1365 s10337 006 0041 5 S2CID 95785346 Parmar Dixit Sugiono Erli Raja Sadiya Rueping Magnus 2014 Complete Field Guide to Asymmetric BINOL Phosphate Derived Bronsted Acid and Metal Catalysis History and Classification by Mode of Activation Bronsted Acidity Hydrogen Bonding Ion Pairing and Metal Phosphates Chemical Reviews 114 18 9047 9153 doi 10 1021 cr5001496 PMID 25203602 Yang Jin Fei Wang Rong Hua Wang Yin Xia Yao Wei Wei Liu Qi Sheng Ye Mengchun 2016 10 11 Ligand Accelerated Direct C H Arylation of BINOL A Rapid One Step Synthesis of Racemic 3 3 Diaryl BINOLs Angewandte Chemie International Edition 55 45 14116 14120 doi 10 1002 anie 201607893 ISSN 1433 7851 PMID 27726256 A practical large scale synthesis of enantiomerically pure 3 bis methoxycarbonyl methyl cyclohexanone via catalytic asymmetric Michael reaction Tetrahedron Volume 58 Issue 13 25 March 2002 Pages 2585 2588 Youjun Xu Ken Ohori Takashi Ohshima Masakatsu Shibasaki doi 10 1016 S0040 4020 02 00141 2 Gopalan Aravamudan S Jacobs Hollie K 2001 04 15 Lithium Aluminum Hydride 2 2 Dihydroxy 1 1 binaphthyl Encyclopedia of Reagents for Organic Synthesis John Wiley amp Sons Ltd doi 10 1002 047084289x rl041 ISBN 0471936235 Retrieved from https en wikipedia org w index php title 1 1 Bi 2 naphthol amp oldid 1215244404, wikipedia, wiki, book, books, library,
