CHÉMIA HETEROCYKLICKÝCH ZLÚČENÍN
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1 CHÉMIA HETEROCYKLICKÝCH ZLÚČEÍ 1. ročník Ing. štúdia odboru Technická chémia Zimný semester 2017/2018 Doc. Ing. Peter Szolcsányi, PhD. Odd. organickej chémie ÚOCHKP Blok A, 3. posch., č.m Web: 1
2 CHÉMIA HETEROCYKLICKÝCH ZLÚČEÍ Použitá a odporúčaná literatúra: J. Alvarez-Builla et al. (Ed.): Modern Heterocyclic Chemistry, Wiley, J. Clayden et al.: Organic Chemistry, Oxford University Press, P. Collins, R. Ferrier: Monosaccharides, Wiley, T. K. Lindhorst: Essentials of Carbohydrate Chemistry and Biochemistry, Wiley, H. Vorbrüggen, C. Ruh-Pohlenz : Handbook of ucleoside Synthesis, Wiley, S. Müller (Ed.): ucleic Acids from A to Z: A Concise Encyclopedia, Wiley, Sylaby a študijné materiály: heterocyklických zlúčenín 2
3 CHÉMIA HETEROCYKLICKÝCH ZLÚČEÍ OH H HO 2 C O CO 2 H S Coniine (jed bolehlavu) metabolit v moči (3-5mg/deň) "plesňová chuť" pokazeného vína O O Et Et O H O H H O S O vonná látka zelených paprík LSD (halucinogén) Viagra ("erektívum") 3
4 Klasifikácia,O,S-heterocyklických zlúčenín earomatické: H H H H H - Dusíkaté (cyklické amíny) - Kyslíkaté (cyklické étery) aziridín O azetidín O pyrolidín piperidín oxirán oxetán THF THP O O azepán - Sírne (cyklické sulfidy) S S S tiirán tietán THT Aromatické (Hückel: 4n+2 P elektrónov): - 5-článkové - 6-článkové Dusíkaté Kyslíkaté Sírne H pyrol O furán S tiofén H imidazol pyridín pyrimidín 4
5 6-Článkové,O-heteroaromáty ázvoslovie 5
6 Pyridín Prírodná látka a bioaktívna molekula 6
7 6-Článkové aromatické heterocykly Pyridín Štruktúra a vlastnosti 1.40 Å 1.39 Å 2.2 D 1.34 Å (b.p. 115 C) 7
8 6-Článkové aromatické heterocykly Pyridín Aromaticita How aromatic are azines in comparison with benzene? (ICS(0)πzz = ucleus-independent Chemical Shift Index, ECREs = Extra Cyclic Resonance Energies) Hetero--substitution has little effect on the aromaticity of benzene. 8
9 6-Článkové aromatické heterocykly Reaktivita pyridínu Analýza vlastností 9
10 6-Článkové aromatické heterocykly Reaktivita pyridínu S EAr ide veľmi zle! 10
11 6-Článkové aromatické heterocykly Reaktivita pyridínu - vs. C-substitúcia S EAr : : 11 11
12 6-Článkové aromatické heterocykly Reaktivita pyridínu Drastické podmienky pre S EAr 12
13 6-Článkové aromatické heterocykly Reaktivita pyridínu utná aktivácia pre S EAr : Mechanism of activation for S EAr via electron-donating substituent(s): - H + 13
14 6-Článkové aromatické heterocykly Reaktivita pyridínu Využitie aktivácie v S EAr : 14
15 6-Článkové aromatické heterocykly Reaktivita pyridínu Regioselektivita S EAr S EAr Frontier electron populations and the sites of nitration 15
16 6-Článkové aromatické heterocykly Pyridín -oxid Príprava a vlastnosti : As a pure substance, m-cpba is a white powder (m.p. 93 C), which can be detonated by shock or by sparks. It is therefore sold commercially as a stable aq. mixture with 72% m-cpba. CAUTIO: m-cpba is a strong oxidizing agent that may cause fire upon contact with flammable material!!! 16
17 6-Článkové aromatické heterocykly Pyridín -oxid Reaktivita : - H + : (P=O bond: 575 kj/mol) 17
18 6-Článkové aromatické heterocykly Reaktivita pyridínu S Ar ide veľmi dobre! : g b vs. a 18
19 6-Článkové aromatické heterocykly Reaktivita pyridínu Regioselektivita S Ar 19
20 6-Článkové aromatické heterocykly Reaktivita pyridínu S Ar ide veľmi dobre! Mechanizmus Ad -E: Ad E a-aminácia: g-tioalkylácia: 20
21 6-Článkové aromatické heterocykly Reaktivita 2- a 4-pyridónu Príprava aktivovaných pyridínov pre S Ar Tautomerism of Oxy-pyridines/Pyridones: The a- and g-systems differ from the b- in terms of reactivity and structure. In the a-case, the equilibrium is highly solvent dependent, but the keto-form is favoured in polar solvents (DMF, MeC). Mechanism of Ad -E: Application of 4-pyridone S Ar : 21
22 6-Článkové aromatické heterocykly Reaktivita pyridínu Syntetické využitie S Ar Flupirtine is a centrally acting non-opioid, non-said, non-steroidal analgesic. It is a selective neuronal K + -channel opener and MDA receptor antagonist. Flupirtine is an efficient analgesic and has a neuro-protective properties. The main concern is possible liver toxicity and rare cardiac effects. 22
23 Reaktivita pyridínu Zhrnutie electrophilic 23
24 6-Článkové aromatické heterocykly Syntéza pyridínov Priemyselná výroba: Laboratórna príprava: 24
25 6-Článkové aromatické heterocykly Hantzschova (retro)syntéza pyridínu Retrosynthesis: Hantzsch (multicomponent 5+1 ) synthesis: 25
26 6-Článkové aromatické heterocykly Hantzschova syntéza pyridínu Mechanizmus 26
27 Arthur Rudolf Hantzsch ( ) PhD. : 1880, Universität Würzburg (Prof. Johannes Wislicenus) Profesor organickej chémie: , Eidgenössisches Polytechnikum Zürich , Universität Würzburg , Universität Leipzig Syntéza pyridínu: 1882 Syntéza tiazolu: 1889 Položil základy syntézy heterocyklických zlúčenín a zaviedol ich nomenklatúru. Zaoberal sa štúdiom stereochémie, kryoskopie a ÚV spektroskopie. 27
28 Príprava 1,4-dihydropyridínových liečiv Amlodipín, Felodipín More than 12 important drugs containing the 1,4-DHP nucleus were clinically used worldwide so far. Amlodipine and felodipine are long-acting calcium channel blockers used to control hypertension. They act by relaxing the smooth muscle in the arterial wall, decreasing total peripheral resistance and hence reducing blood pressure; in angina pectoris it increases blood flow to the heart muscle. 28
29 6-Článkové aromatické heterocykly Pyrimidín Štruktúra, vlastnosti a príprava In pyrimidine, both -atoms are equivalent and sp 2 -hybridised. The electron lone pairs lie outside the ring and are not conjugated with the aromatic p-system. Therefore, pyrimidine is slightly basic, although less than a pyridine. The reason is the inductive, electron-withdrawing effect of the second -atom (cf. pk ah = 1.3 vs. pk ah = 5.2 (pyr)). 4 Pyrimidine Low melting solid m.p 21 C, b.p. 123 C Found in meteorites! Perpendicular lone pairs Concept of Pinner s pyrimidine synthesis: Resonance energy: 110 kj/mol (cf. benzene: RE = 150kJ/mol) Aromaticity index: 67% (cf. benzene: AI = 100%) 29
30 Príprava pyrimidínových liečiv Trimethoprim Retrosyntéza 30
31 Príprava pyrimidínových liečiv Trimethoprim Syntéza Trimethoprim is a bacteriostatic antibiotic mainly used in the treatment of urinary tract infections. It acts by interfering with dihydrofolate reductase, inhibiting synthesis of tetrahydrofolic acid. The combination of trimethoprim with antibiotic sulfamethoxazole is known as cotrimoxazole. Use of trimethoprim is contraindicated during pregnancy, especially the first trimester. 31
32 6-Článkové aromatické heterocykly Pyrazín Prírodný výskyt a bioaktivita HO Austrálska orchidea (Drakaea livida) Sexuálny feromón osy, Opeľovací atraktant orchidey Austrálska osa (Zaspilothynnus nigripes) Galbazín zelená vôňa (2-metoxy-3-izobutylpyrazín) Cabernet Sauvignon Blanc 32
33 6-Článkové aromatické heterocykly Pyrazín Štruktúra a vlastnosti Both -atoms contribute 1 electron each to the aromatic p-system, lone pairs are in sp 2 orbital in the ring plane. Due to the strong electron-withdrawing effect of -atoms, pyrazine is an electron-defficient heteroaromate. Pyrazine (pk ah = 0.4) and pyridazine (pk ah = 2.3) are significantly less basic than pyridine (pk ah = 5.2). Resonance energy: 100 kj/mol (cf. benzene: RE = 150 kj/mol) Aromaticity index: 75% (cf. benzene: AI = 100%) Colourless prisms (m.p. 57 C, b.p. 116 C) (I. Pavlakos et al.: Angew. Chem. Int. Ed. 2015, 54, ) 33
34 6-Článkové aromatické heterocykly Pyrazín Príprava Concept of two component coupling: (a) (b) (a) Cyclocondensation of aminoketones to 2,5-dihydropyrazines with their subsequent oxidation to 1,4-diazines. - 2 H 2 O [O] (b) Cyclocondensation of dicarbonyls and diamines to 2,3-dihydropyrazines with subsequent oxidation to pyrazines. - 2 H 2 O [O] 34
35 6-Článkové aromatické heterocykly Pyrazín Reaktivita OXIDATIO: Pyrazines form, -dioxides easily, the regiochemistry is influenced by steric and/or inductive effects. Alkyl substituents and fused aromatic rings can be oxidised to carboxylic acids leaving the aromatic ring untouched. HALOGEATIO: Pyrazines are resistant to electrophilic substitution and susceptible to nucleophilic substitution. Due to highly electron-defficient heteroaromatic ring, the chlorination likely proceeds via addition/elimination sequence. ALKYLATIO: Halopyrazines readily undergo S Ar with soft C,,O,S-nucleophiles via substitution of the halide. (Ad -E) 35
36 Benzo-fúzované pyridíny (Izo)Chinolíny Antimalarikum z chinínovníka (Cinchona pubescens) Ópiový alkaloid z makovíc (Papaver somniferum) 36
37 Benzo-fúzované pyridíny 8-hydroxychinolín Prírodné antibiotikum OH Patogénna baktéria (Clostridium difficile) Spôsobuje hnačky Korene americkej rastliny Sebastiania corniculata obsahujú chinolínové alkaloidy Prospešná baktéria (Bifidobacterium longum) Súčasť mikrobiómu Selective growth-inhibitory effect of 8-hydroxyquinoline towards Clostridium difficile and Bifidobacterium longum. (J. ováková et al.: J. Med. Microbiol., doi: /jmm ) 37
38 Benzo-fúzované pyridíny 8-hydroxychinolín Intermolekulové vodíkové väzby AFM AFM The first visualisation of a intermolecular hydrogen bond of 8-hydroxyquinoline using atomic force microscopy (AFM). (J. Zhang et al.: Science DOI: /science ) 38
39 Benzo-fúzované pyridíny (Izo)Chinolíny Reaktivita S EAr HOC (pk ah 4.9) HOC S EAr S EAr Frontier electron populations (pk ah 5.4) 39
40 Benzo-fúzované pyridíny Chinolóny O O H O 2-pyridón H 2-chinolón O H 4-pyridón H 4-chinolón Pefloxacín a rosoxacín sú synt etické širokospektrálne chemoterapeutiká na liečbu život ohrozujúcich infekcií. Sú aktívne voči Gram-pozitívnym aj Gram-negatívnym baktériám, inhibujú DA-gyrázu a topoizomerázu II., IV. Pefloxacín a rosoxacín patria do poslednej línie antibiotickej liečby, ich nevýhodou je rýchly nástup rezistencie. F O CO 2 H O CO 2 H Me Et Et Abaktal (pefloxacín) /Lek Pharmaceuticals/ Eradacil (rosoxacín) /Sanofi-Aventis/ ATIMIKROBIÁLE CHIOLÓOVÉ ATIBIOTIKÁ 40
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