Allenlar

Organik kimyoda allenlar organik birikmalar boʻlib, ularda bitta uglerod atomi oʻzining ikkita qoʻshni uglerod markazining har biri bilan qo'sh bog'lanishga (C=C=C) ega. Allenlar toʻplangan dienlar ham hisoblanadi. Ushbu sinfning asosiy birikmasi propadien boʻlib, allenlar sinifiga mansub. Allen tipidagi tuzilishga ega, ammo uchdan ortiq uglerod atomiga ega boʻlgan birikmalar kumulenlar deb ataladi.

Tarixi

Koʻp yillar davomida allenlar qiziqish sifatida qaralgan, ammo sintetik jihatdan foydasiz va ularni tayyorlash, ishlash qiyin deb hisoblangan^[1]^[2]. Maʼlum boʻlishicha^[3] allen, glutin kislotasining birinchi sintezi boʻlib, birikmalar sinfi mavjudligini isbotlash maqsadida^[4]^[5] 1950 — 2012-yilgacha allenlar boʻyicha 300d an ortiq maqola chop etildi^[6]. Bu birikmalar nafaqat qiziqarli oraliq mahsulotlar, balki sintetik jihatdan qimmatli maqsadlarda masalan, 150 dan ortiq tabiiy mahsulotlar allen yoki kumulen tarkibi bilan maʼlum.

Tuzilishi va xususiyatlari

Geometriya tuzilishi

Propadienning 3D koʻrinishi (allen)

Allenlarning markaziy uglerod atomi ikkita sigma bogʻ va ikkita pi bogʻ hosil qilib birikadi. Markaziy uglerod atomi sp-gibridlangan va ikkita uglerod atomi sp² — gibridlangan. Uchta uglerod atomi tomonidan hosil qilingan bogʻlanish burchagi 180° boʻlib, markaziy uglerod atomi uchun chiziqli geometriyani koʻrsatadi. Ikkita uglerod atomi tekis boʻlib, bu tekisliklar bir-biridan 90°ga farq qiladi. Tuzilish strukturasi metanga oʻxshash shaklda „kengaytirilgan tetraedral“ sifatida ham koʻrish mumkin, bu oʻxshashlik maʼlum lotin molekulalarining stereokimyoviy tahlilida hosil boʻladi.

Simmetriya tuzilishi

Allenlarning simmetriyasi va izomeriyasi uzoq vaqtdan beri organik kimyogarlarni hayratda qoldirdi. Allenlar uchun markaziy uglerod atomi orqali molekulasining ikkala uchida CH₂ tekisligi 45°ga egilgan va ikkita ikki tomonlama aylanish oʻqi mavjud. Shunday qilib, molekulani ikki qanotli pervanel deb hisoblash mumkin. C=C=C bogʻlanishlari orqali uchinchi ikki qavatli aylanish oʻqi oʻtadi. Shunday qilib, molekulalarning bu sinfi D_2d nuqta guruhiga mansub. Simmetriyasi sababli dipol momentga ega emas, yaʼni u qutbsiz molekuladir.

Kimyoviy va spektral xossalari

Allenlarning kimyoviy xossalari jihatidan boshqa alkenlardan ancha farq qiladi. Ajratilgan va konyugatsiyalangan dienlar bilan solishtirganda ular ancha barqaror emas. Allenlarni hosil boʻlish issiqligi, izomerik pentadienlar bilan solishtirganda 1,2-pentadien uchun 33,6 kkal/mol. 1.3-pentadien uchun esa 18,1 kkal/mol va 1,4-pentadien uchun 25,4 kkal/mol^[7].

Allenlarning ¹³C NMR spektri sp-gibridlangan uglerod atomining signali bilan xarakterlanadi va 200-220 ppmda rezonanslanadi. Bundan farqli oʻlaroq, sp²-gibridlangan uglerod atomlari alkin va nitril uglerod atomlari uchun xos boʻlgan hududda 80 ppm atrofida rezonanslanadi, terminal allenning CH₂ guruhining protonlari esa 4,5 ppm atrofida rezonanslanadi — bu vinillik protonning biroz yuqorisida roʻy beradi^[8].

Allenlar boy siklo yuklanish kimyosiga ega, jumladan, [4+2] va [2+2] qoʻshilish usullari^[9]^[10] hamda metallar tomonidan katalizlangan rasmiy siklo yuklanish jarayonlarida ishtirok etadi^[11]^[12]. Shuningdek allenlar metallning katalizlangan gidrofunksionalizatsiya reaksiyalari uchun substrat boʻlib xizmat qiladi^[13]^[14]^[15].

Sintezlanishi

Allenlar koʻpincha maxsus sintezni talab qilsa-da, propadien sanoatda keng miqyosda metilatsetilen bilan muvozanat aralashmasi sifatida ishlab chiqariladi.

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MAPP gazi sifatida tanilgan ushbu aralashma savdo sifatida mavjud. 298 Kda bu reaksiyaning ΔG°si −1,9 kkal/mol, K_ekv = 24,7ga mos keladi^[16].

Sintezlangan birinchi allenni 1887-yilda Burton va Pechmann tomonidan penta-2,3-diendioik kislotasi yaratilgan. Biroq, strukturasi 1954-yilda aniqlangan^[17].

Koʻpgina halqalar yoki halqa tizimlari yarim tizimli nomlar bilan maʼlum boʻlib, ular toʻplanmagan aloqalarning maksimal sonini oʻz ichiga oladi. Yigʻilgan bogʻlanishlarni (va shuning uchun skeletdan kutilganidan kamroq vodorod atomlarini) oʻz ichiga olgan hosilalarni bir maʼnoda belgilash uchun kichik deltadan ushbu atomdan toʻplangan qoʻsh aloqalar sonini koʻrsatadigan pastki belgisi bilan foydalanish mumkin, masalan, 8d² -benzosiklonon. Bu nostandart valentlik holatlarini belgilash uchun l-konventsiya bilan birlashtirilishi mumkin, masalan, 2l ⁴ d ² ,5l ⁴ d ² -tieno[3,4-c]tiofen. ^[18]

Yana qarang

Uch yoki undan ortiq qoʻshni uglerod-uglerod qoʻsh bogʻlari boʻlgan birikmalar kumulenlar deb ataladi.

Manbalar

↑ The Chemistry of the Allenes (vol. 1−3); Landor, S. R., Ed.; cademic Press: London, 1982.
↑ Taylor, David R. (1967-06-01). "The Chemistry of Allenes" (en). Chemical Reviews 67 (3): 317–359. doi:10.1021/cr60247a004. ISSN 0009-2665. https://pubs.acs.org/doi/abs/10.1021/cr60247a004.
↑ Hoffmann-Röder, Anja; Krause, Norbert (2004-02-27). "Synthesis and Properties of Allenic Natural Products and Pharmaceuticals" (en). Angewandte Chemie International Edition 43 (10): 1196–1216. doi:10.1002/anie.200300628. ISSN 1433-7851. PMID 14991780. https://onlinelibrary.wiley.com/doi/10.1002/anie.200300628.
↑ Burton, B. S.; von Pechmann, H. (January 1887). "Ueber die Einwirkung von Chlorphosphor auf Acetondicarbonsäureäther" (de). Berichte der Deutschen Chemischen Gesellschaft 20 (1): 145–149. doi:10.1002/cber.18870200136. https://onlinelibrary.wiley.com/doi/10.1002/cber.18870200136.
↑ Jones, E. R. H.; Mansfield, G. H.; Whiting, M. C. (1954). "Researches on acetylenic compounds. Part XLVII. The prototropic rearrangements of some acetylenic dicarboxylic acids" (en). Journal of the Chemical Society (Resumed): 3208–3212. doi:10.1039/jr9540003208. ISSN 0368-1769. http://xlink.rsc.org/?DOI=jr9540003208.
↑ Data from the Web of Science database.
↑ Informatics, NIST Office of Data and (1997) (en). Welcome to the NIST WebBook. doi:10.18434/T4D303. https://webbook.nist.gov/index.html.en-us.en. Qaraldi: 2020-10-17. Allenlar]]
↑ Pretsch, Ernö, 1942-. Structure determination of organic compounds : tables of spectral data, Bühlmann, P. (Philippe), 1964-, Badertscher, M., Fourth, Revised and Enlarged, Berlin: Springer, 2009. ISBN 978-3-540-93810-1. OCLC 405547697.
↑ Alcaide, Benito; Almendros, Pedro; Aragoncillo, Cristina (2010-01-28). "Exploiting [2+2 cycloaddition chemistry: achievements with allenes"] (en). Chemical Society Reviews 39 (2): 783–816. doi:10.1039/B913749A. ISSN 1460-4744. PMID 20111793. https://pubs.rsc.org/en/content/articlelanding/2010/cs/b913749a.
↑ Pasto, Daniel J. (January 1984). "Recent developments in allene chemistry" (en). Tetrahedron 40 (15): 2805–2827. doi:10.1016/S0040-4020(01)91289-X. https://linkinghub.elsevier.com/retrieve/pii/S004040200191289X.
↑ Alcaide, Benito; Almendros, Pedro (August 2004). "The Allenic Pauson−Khand Reaction in Synthesis" (en). European Journal of Organic Chemistry 2004 (16): 3377–3383. doi:10.1002/ejoc.200400023. ISSN 1434-193X. http://doi.wiley.com/10.1002/ejoc.200400023.
↑ Mascareñas, José L.; Varela, Iván; López, Fernando (2019-02-19). "Allenes and Derivatives in Gold(I)- and Platinum(II)-Catalyzed Formal Cycloadditions" (en). Accounts of Chemical Research 52 (2): 465–479. doi:10.1021/acs.accounts.8b00567. ISSN 0001-4842. PMID 30640446. PMC 6497370. //www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=6497370.
↑ Zi, Weiwei; Toste, F. Dean (2016-08-08). "Recent advances in enantioselective gold catalysis" (en). Chemical Society Reviews 45 (16): 4567–4589. doi:10.1039/C5CS00929D. ISSN 1460-4744. PMID 26890605. https://pubs.rsc.org/en/content/articlelanding/2016/cs/c5cs00929d.
↑ Lee, Mitchell; Nguyen, Mary; Brandt, Chance; Kaminsky, Werner; Lalic, Gojko (2017-12-04). "Catalytic Hydroalkylation of Allenes" (en). Angewandte Chemie International Edition 56 (49): 15703–15707. doi:10.1002/anie.201709144. PMID 29052303.
↑ Kim, Seung Wook; Meyer, Cole C.; Mai, Binh Khanh; Liu, Peng; Krische, Michael J. (2019-10-04). "Inversion of Enantioselectivity in Allene Gas versus Allyl Acetate Reductive Aldehyde Allylation Guided by Metal-Centered Stereogenicity: An Experimental and Computational Study". ACS Catalysis 9 (10): 9158–9163. doi:10.1021/acscatal.9b03695. PMID 31857913. PMC 6921087. //www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=6921087.
↑ Robinson, Marin S.; Polak, Mark L.; Bierbaum, Veronica M.; DePuy, Charles H.; Lineberger, W. C. (1995-06-01). "Experimental Studies of Allene, Methylacetylene, and the Propargyl Radical: Bond Dissociation Energies, Gas-Phase Acidities, and Ion-Molecule Chemistry". Journal of the American Chemical Society 117 (25): 6766–6778. doi:10.1021/ja00130a017. ISSN 0002-7863. https://doi.org/10.1021/ja00130a017.
↑ Jones, E. R. H.; Mansfield, G. H.; Whiting, M. C. (1954-01-01). "Researches on acetylenic compounds. Part XLVII. The prototropic rearrangements of some acetylenic dicarboxylic acids" (en). Journal of the Chemical Society (Resumed): 3208–3212. doi:10.1039/JR9540003208. ISSN 0368-1769. https://pubs.rsc.org/en/content/articlelanding/1954/jr/jr9540003208.
↑ "Nomenclature for cyclic organic compounds with contiguous formal double bonds (the δ-convention)". Pure Appl. Chem. 60: 1395-1401. 1988. doi:10.1351/pac198860091395. http://www.chem.qmul.ac.uk/iupac/hetero/De.html.

Adabiyotlar

Brummond, Kay M. (muharrir). Allen kimyosi (maxsus tematik masala). Beilstein Journal of Organic Chemistry 7: 394-943.

Tashqi manbalar

Allenlarning sintezi

[:0-1] The Chemistry of the Allenes (vol. 1−3); Landor, S. R., Ed.; cademic Press: London, 1982.

[:2-2] Taylor, David R. (1967-06-01). "The Chemistry of Allenes" (en). Chemical Reviews 67 (3): 317–359. doi:10.1021/cr60247a004. ISSN 0009-2665. https://pubs.acs.org/doi/abs/10.1021/cr60247a004.

[:1-3] Hoffmann-Röder, Anja; Krause, Norbert (2004-02-27). "Synthesis and Properties of Allenic Natural Products and Pharmaceuticals" (en). Angewandte Chemie International Edition 43 (10): 1196–1216. doi:10.1002/anie.200300628. ISSN 1433-7851. PMID 14991780. https://onlinelibrary.wiley.com/doi/10.1002/anie.200300628.

[4] Burton, B. S.; von Pechmann, H. (January 1887). "Ueber die Einwirkung von Chlorphosphor auf Acetondicarbonsäureäther" (de). Berichte der Deutschen Chemischen Gesellschaft 20 (1): 145–149. doi:10.1002/cber.18870200136. https://onlinelibrary.wiley.com/doi/10.1002/cber.18870200136.

[5] Jones, E. R. H.; Mansfield, G. H.; Whiting, M. C. (1954). "Researches on acetylenic compounds. Part XLVII. The prototropic rearrangements of some acetylenic dicarboxylic acids" (en). Journal of the Chemical Society (Resumed): 3208–3212. doi:10.1039/jr9540003208. ISSN 0368-1769. http://xlink.rsc.org/?DOI=jr9540003208.

[6] Data from the Web of Science database.

[7] Informatics, NIST Office of Data and (1997) (en). Welcome to the NIST WebBook. doi:10.18434/T4D303. https://webbook.nist.gov/index.html.en-us.en. Qaraldi: 2020-10-17. Allenlar]]

[8] Pretsch, Ernö, 1942-. Structure determination of organic compounds : tables of spectral data, Bühlmann, P. (Philippe), 1964-, Badertscher, M., Fourth, Revised and Enlarged, Berlin: Springer, 2009. ISBN 978-3-540-93810-1. OCLC 405547697.

[9] Alcaide, Benito; Almendros, Pedro; Aragoncillo, Cristina (2010-01-28). "Exploiting [2+2 cycloaddition chemistry: achievements with allenes"] (en). Chemical Society Reviews 39 (2): 783–816. doi:10.1039/B913749A. ISSN 1460-4744. PMID 20111793. https://pubs.rsc.org/en/content/articlelanding/2010/cs/b913749a.

[10] Pasto, Daniel J. (January 1984). "Recent developments in allene chemistry" (en). Tetrahedron 40 (15): 2805–2827. doi:10.1016/S0040-4020(01)91289-X. https://linkinghub.elsevier.com/retrieve/pii/S004040200191289X.

[11] Alcaide, Benito; Almendros, Pedro (August 2004). "The Allenic Pauson−Khand Reaction in Synthesis" (en). European Journal of Organic Chemistry 2004 (16): 3377–3383. doi:10.1002/ejoc.200400023. ISSN 1434-193X. http://doi.wiley.com/10.1002/ejoc.200400023.

[12] Mascareñas, José L.; Varela, Iván; López, Fernando (2019-02-19). "Allenes and Derivatives in Gold(I)- and Platinum(II)-Catalyzed Formal Cycloadditions" (en). Accounts of Chemical Research 52 (2): 465–479. doi:10.1021/acs.accounts.8b00567. ISSN 0001-4842. PMID 30640446. PMC 6497370. //www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=6497370.

[13] Zi, Weiwei; Toste, F. Dean (2016-08-08). "Recent advances in enantioselective gold catalysis" (en). Chemical Society Reviews 45 (16): 4567–4589. doi:10.1039/C5CS00929D. ISSN 1460-4744. PMID 26890605. https://pubs.rsc.org/en/content/articlelanding/2016/cs/c5cs00929d.

[14] Lee, Mitchell; Nguyen, Mary; Brandt, Chance; Kaminsky, Werner; Lalic, Gojko (2017-12-04). "Catalytic Hydroalkylation of Allenes" (en). Angewandte Chemie International Edition 56 (49): 15703–15707. doi:10.1002/anie.201709144. PMID 29052303.

[15] Kim, Seung Wook; Meyer, Cole C.; Mai, Binh Khanh; Liu, Peng; Krische, Michael J. (2019-10-04). "Inversion of Enantioselectivity in Allene Gas versus Allyl Acetate Reductive Aldehyde Allylation Guided by Metal-Centered Stereogenicity: An Experimental and Computational Study". ACS Catalysis 9 (10): 9158–9163. doi:10.1021/acscatal.9b03695. PMID 31857913. PMC 6921087. //www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=6921087.

[16] Robinson, Marin S.; Polak, Mark L.; Bierbaum, Veronica M.; DePuy, Charles H.; Lineberger, W. C. (1995-06-01). "Experimental Studies of Allene, Methylacetylene, and the Propargyl Radical: Bond Dissociation Energies, Gas-Phase Acidities, and Ion-Molecule Chemistry". Journal of the American Chemical Society 117 (25): 6766–6778. doi:10.1021/ja00130a017. ISSN 0002-7863. https://doi.org/10.1021/ja00130a017.

[17] Jones, E. R. H.; Mansfield, G. H.; Whiting, M. C. (1954-01-01). "Researches on acetylenic compounds. Part XLVII. The prototropic rearrangements of some acetylenic dicarboxylic acids" (en). Journal of the Chemical Society (Resumed): 3208–3212. doi:10.1039/JR9540003208. ISSN 0368-1769. https://pubs.rsc.org/en/content/articlelanding/1954/jr/jr9540003208.

[18] "Nomenclature for cyclic organic compounds with contiguous formal double bonds (the δ-convention)". Pure Appl. Chem. 60: 1395-1401. 1988. doi:10.1351/pac198860091395. http://www.chem.qmul.ac.uk/iupac/hetero/De.html.

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