
nucleophilic aarometik substitution

nucleophile oru sugandha valayathil halide polulla oru nalla leaving groupine sthaanabhrashtamaakkunna jaiva rasathanthrathile oru pakara prathikaranamaanu nucleophilic aarometik substitution. sugandha valayangal saadhaaranayaayi nucleophilic aanu, ennaal chila sugandha samyukthangal nucleophilic pakaratthinu vidheyamaakunnu. electron-valikkunna pakarakkar vahichaal saadhaaranayaayi nucleophilic aalkkeenukalkk konjugettu pakarakkaranaakkaan kazhiyunnathupole, sariyaaya pakarakkar undengil saadhaaranayaayi nucleophilic sugandha valayangalum electrophilic aayi maarunnu.eee prathikaranam oru saadhaarana sn2 prathikaranatthil ninnu vyathyasthamaan, kaaranam ithu oru trikona kaarban aattathilaan (ezz. pii. 2 hybridisation) sambhavikkunnath. benzene valayathinte sterik thadassam kaaranam sn2 prathikaranatthinte samvidaanam sambhavikkunnilla. sii aattathe aakramikkunnathin, nucleophile benzene valayam sthithicheyyunna pinbhaagathu ninnulla sii-elji (leaving group) bondinu anusrithamaayi sameepikkanam. oru tetrahedral kaarban aattathil maathram sn2 prathikaranangal sambhavikkunna pothuvaaya niyamam ithu pinthudarunnu. 
sn1 samvidaanam saadhyamaan, pakshe leaving group asaadhaaranamaamvidham nallathallengil valare prathikoolamaanu. athil leaving groupinte sahayamillaathe nashtappedunnathum oru aaril kaatteshan roopeekarikkunnathum ulppedum. sn1 prathikaranangalil idanilakkaaraayi upayogikkunna ellah kaattiyanukalum shoonyamaaya pii orbittalulla planaraayirunnu. eee kaatteshan planner aanenkilum pii oorbittal niranjirikkunnu (ithu sugandha valayathinte bhagamaanu) koodaathe shoonyamaaya oorbittal valayathinu purathulla oru sp2 oorbitalaanu.
sugandha valayangal nucleophilic pakaratthinu vidheyamaakunna aarr vyathyastha samvidaanangalundu.
nucleophilic aarometik substitution mekkaanisangal.
sugandha samvidaanangal neridunna 6 nucleophilic pakara samvidaanangalundu
ithil ettavum pradhaanappettath snarr mechanisamaanu. electron pinvalikkunna grouppukal nucleophilic aakramanathilekku valayathe sajeevamaakkunnu. udaaharanathinu, halide leaving groupil oortho allengil paaraa sthaapichirikkunna naitro functional grouppukal undengil, snarr mechanism anukoolamaanu.
snarr prathikarana samvidaanam.
vellathile oru adisthaana laayaniyil 2,4-dinitrochlorobensine enna nucleophilic sugandha pakarakkaarante prathikarana samvidaanam thaazhepparayunnavayaanu.
eee kramatthil kaarban attangal chlorin aattavumaayi bandhippichirikkunna 12 manikk 1 carbonil ninnu aarambhich 1 muthal 6 vare gadikaaradishayil ennappedunnu. naitro group nucleophilic pakarakkaranaayulla oru aaktivettarum mettaa director aayathinal, athu bandhikkappettirikkunna benzene kaarban aattathin negatteevu charge undakaan ithu anuvadikkunnu. mysenheimer samuchayathil, kaarbaniyante nonbonded electronukal sugandha paii sisttavumaayi bandhikkappedunnu, ithu ipso kaarban aattathe hydroxyl grouppumaayi (-oo. echu) thaalkkaalikamaayi bandhikkaan anuvadikkunnu. kuranja oorjjaavasthayilekku madangunnathinu, onnukil hydroxyl group pookunnu, allengil chloride pookunnu. parihaaratthil rund prakriyakalum sambhavikkunnu. intermediattinte oru cheria sathamaanam chloride nashtappettu ulppannamaayi (2,4-dinitrophenol) maarunnu, bakkiyullava reactantilekku madangunnu. 2, 4-dinitrophenol kuranja oorjjaavasthayilullathinaal athu riyaaktant roopeekarikkaan madangivarilla, athinaal kurachu samayathinu sesham, prathikaranam 2,4-dinitrophenoline anukoolikkunna raasa santhulithaavasthayilethunna.
sugandha prathipravarthanathekkaal uyarnna oorjjaavasthayilullathinaal anurananm-sthirathayulla mysenheimer complexinte roopeekaranam mandagathiyilaanu. chloridinte nashtam vegathilaanu, kaaranam valayam veendum sugandhamullathaayi maarunnu. sameepakaala padanangal soochippikkunnathu, chilappol, maisenheimer complexes ellaayppozhum oru yadhaartha intermediat allah, marichu oru 'frondside sn 2' prakriyayude parivartthana avasthayaayirikkaam, prathyekichu electron-droying grouppukalude sthiratha valare shakthamallengil. atharam 'samyojitha snarr' prathikaranangal munbu anumaanichathinekkaal kooduthalaanennu 2019 leeii oru avalokanam vaadikkunnu.
aaril haalaidukalkk classic 'baxide' sn2 prathikaranatthinu vidheyamaakaan kazhiyilla. kaarban aattathin trikona samatulita jyamiti ullathinaal kaarban-halojan boond valayathinte prathalatthilaanu. pinvashatthe akramanam thadayappettathinaal eee prathikaranam saadhyamalla. oru sn1 prathikaranam saadhyamaan, pakshe valare prathikoolamaanu. athil leaving groupinte sahayamillaathe nashtappedunnathum oru aaril kaatteshan roopeekarikkunnathum ulppedum. naitro grouppaanu ettavum saadhaaranayaayi kaanapedunna sajeeva group, mattu grouppukal syaano, asail grouppaanu. vidunna group oru halojan allengil sulfide aakam. vardhichuvarunna electronegattivitti anusarichu nucleophilic aakramanathinulla prathikarana nirakk vardhikkunnu. kaaranam, oru snarr prathikaranatthinte nirakk nirnnayikkunna ghattam nucleophylinte aakramanavum thudarnnulla sugandhavyavasthayude thakarchayumaanu; vidunna grouppinte nashtatthinu sesham sugandhavyavasthayude anukoolamaaya parishkaranamaanu vegathayeriya prakriya. athinaal, snaarinulla group seshiye vidunna halojan sambandhichu inipparayunna paatten kaanapedunnu f> cl ±br> i (i.iii. oru sn2 prathikaranatthinu prathekshikkunna oru vipareeta kramam). oru sn2 prathikaranatthinte veekshanakonil ninnu nokkukayaanenkil ithu vipareethabodhamullathayi thonnum, kaaranam sii-eph boond jaiva rasathanthrathile ettavum sakthamaaya onnaanu, sii-eph bondinte angeyattatthe dhruveekaranam kaaranam fluoride oru snaarin anuyojyamaaya grouppaanu. nucleophylukal aminukal, alcoxideukal, sulfideukal, sthirathayulla carbononukal ennivayaakaam.
nucleophilic aarometik substitution prathikaranangal.
arinukalile chila saadhaarana pakara prathikaranangal chuvade pattikappedutthiyirikku.
nucleophilic aarometik substitution arinukalil maathram parimithappedunnilla, ennirunnaalum hetteroareenukalumaayi prathikaranam kooduthal eluppathil sambhavikkunnu. sugandhamulla oortho positionilo sugandhamulla paaraa positionilo maattisthaapikkumbol pyridinukal prathyekichum prathipravartthikkunnu, kaaranam appol negatteevu charge naitrajan sthaanathu phalapradamaayi delocalise cheyyappedunnu. oru classic prathikaranamaanu chichibabin prathikaranam (alexey chichibabin, 1914), athil pyridine soodiyam amide polulla kshara-loha amaidumaayi prathipravartthichu 2-aminopyridine roopappedunnu.
methyl 3-nitropyridine-4-carboxylate samyukthathil, "mettaa" naitro group yadhaarthathil 120 digri selshyasil dii. emm. ezz. oyil seeshyam fluoridemaayi fluorin upayogichu sthaanabhramsham varuthunnu.
asamamaya nucleophilic aarometik substitution.
1, 3-dicarbonyl samyukthangal polulla kaarban nucleophylukal upayogichu kairal thanmaathrakalude asamamaya samanvayathinulla oru reethiyaayi prathikaranam theliyikkappettittund. 2005-ll aadyamaayi report cheyyappetta oorgaanokaattalist (oru ghatta kaimatta kaattalistumaayi eratta rolil) synconidinil (n, o ennivayil benzylated) ninnaan uruthirinjathu.