Indima kunye neeMechanism zeSodium Cyanide kwi-Organic Synthesis

intshayelelo

Sodium benqanda (I-NaCN), ikristale emhlophe eqinileyo enyibilikayo kakhulu emanzini, zombini isiseko esomeleleyo kunye ne-nucleophile enamandla, iyenza i-reagent exabisekileyo Ukuhlanganiswa kwendalo. Ngaphandle kobutyhefu obugqithisileyo, obufuna amanyathelo angqongqo okhuseleko ngexesha lokuphatha, Isodium cyanide idlala indima ebalulekileyo ekudityanisweni kweekhompawundi ezahlukeneyo zezinto eziphilayo, kubandakanywa amayeza, imichiza yezolimo, kunye neepolima.

Indima yeSodium Cyanide kwi-Organic Synthesis

I-Cyanide Ion njengeNucleophile

The i-cyanide ion ngaphakathi Isodium cyanide yi-nucleophile esabela kakhulu. Ngenxa yetshaja engalunganga kwi- ICarbon iathom kunye ne-electronegativity ephezulu yeathom ye-nitrogen, inokuhlasela amaziko e-electrophilic kwiimolekyuli ze-organic, ezinje ngamaqela e-carbonyl, ii-alkyl halides, kunye nee-epoxides.

Ukuqulunqwa kweebhondi ze-C - C

Omnye weyona misebenzi ibalulekileyo ye sodium cyanide kwi-organic synthesis kukuyilwa kwekhabhoni entsha - iibhondi zekhabhoni, eziphunyezwe ngokutshintshwa kwe-nucleophilic kunye neempendulo zokongezwa. Ngokomzekelo, xa i-alkyl halide isabela nge-sodium cyanide, i-ion ye-cyanide ithatha indawo ye-halide ion, ekhokelela ekubunjweni kwe-nitrile. Le mpendulo inika indlela elula yokwazisa i-athomu yekhabhoni eyongezelelweyo kwi-molecule. Emva koko, iqela le-nitrile linokuguqulwa libe ngamanye amaqela asebenzayo afana ne-carboxylic acids, i-amines, okanye i-aldehydes ngokusebenzisa iinkqubo ezahlukeneyo zeekhemikhali.

I-Synthesis ye-Amino Acids-I-Rection ye-Strecker

I-sodium cyanide yinxalenye ephambili kwi-Strecker reaction, esetyenziselwa ukuhlanganiswa kwe-α - amino acids. Kule mpendulo, i-aldehyde okanye i-ketone idibanisa ne-ammonium chloride kunye ne-sodium cyanide ukwenza i-α - amino nitrile. Le α - i-amino nitrile inokuthi ke i-hydrolyzed ukuvelisa i-α ehambelanayo - i-amino acid.

Ukusabela kwenzeka ngamanyathelo amaninzi: Okokuqala, iqela le-carbonyl ye-aldehyde okanye i-ketone idlula i-protonation, inyusa i-electrophilicity yayo. Emva koko, imolekyuli ye-ammonia ihlasela iqela le-protonated carbonyl, ilandelwa yi-deprotonation ukwenza i-hemiaminal. Okulandelayo, iqela le-hydroxyl ye-hemiaminal i-protonated, okubangelwa ukupheliswa kwamanzi kunye nokubunjwa kwe-ion ioni. Iyoni yecyanide emva koko ihlasela ioniyinium ukuze ivelise i-α - amino nitrile. Ekugqibeleni, i-hydrolysis ye-α - i-amino nitrile phambi kwe-asidi okanye isiseko inika i-α-amino acid.

I-Synthesis ye-Nitriles esuka kwi-Aryl Halides-i-Rosenmund-von Braun Reaction

Kwi-Rosenmund-von Braun reaction, i-sodium cyanide isetyenziselwa ukuguqula i-aryl halides, eyi-halogen - endaweni ye-aromatics compounds, kwi-aryl nitriles. I-Catalyzed yi-copper (I) cyanide kwaye ihlala ifuna amaqondo obushushu aphezulu, le mpendulo ibandakanya ukwenziwa kobhedu - iaryl ephakathi. Iyoni yecyanide esuka kwisodium cyanide emva koko idibana nalo mda ukuze yenze iaryl nitrile. Le nkqubo ibalulekile ukwazisa iqela elisebenzayo le-nitrile kwiringi enuka kamnandi, enokuthi iphinde ilungiswe ukuze kuxutywe iikhompawundi ezahlukeneyo ezinuka kamnandi, ezifana namayeza kunye nedayi.

Ukuhlanganiswa kweCarbonyl Compounds

I-sodium cyanide nayo ithatha inxaxheba kwi-synthesis ye-carbonyl compounds. Ngokomzekelo, xa isabela nge-epoxide, i-ion ye-cyanide ihlasela i-athomu ye-carbon engaphantsi endaweni ye-epoxide, ebangela ukuba i-ring ivuleke. I-hydrolysis elandelayo ye-cyanohydrin ebangelwayo ingakhokelela ekwenziweni kwe-carbonyl compound.

IiNdlela zokuSebenza eziBandakanya iSodium Cyanide

Nucleophilic Substitution Reactions

SN2 Inkqubo: Xa i-sodium cyanide isabela nge-alkyl halides ephambili, ukusabela ngokuqhelekileyo kulandela i-SN2 (i-bimolecular nucleophilic substitution) indlela. I-cyanide ion ihlasela i-athomu yekhabhoni efakwe kwi-halogen ukusuka ngasemva, ngokuchasene nendawo ye-ion ye-halide eshiya. Le yimpendulo edibeneyo apho ukwaphulwa kwe-carbon - halogen bond kunye nokwakhiwa kwebhondi ye-carbon-cyanide yenzeke ngaxeshanye. Ireyithi yokusabela ixhomekeke kugxininiso lwe-alkyl halide kunye ne-ion ye-cyanide, kunye ne-stereochemistry yemveliso iguqulwe ngokuthelekiswa neyokuqala.

SN1 Inkqubo: Nge-alkyl halides ephezulu, ukusabela kunokuqhubeka nge-SN1 (unimolecular nucleophilic substitution) indlela. Okokuqala, i-alkyl halide iyahlukana ukuze yenze i-carbocation ephakathi. Emva koko, i-cyanide ion ihlasela le carbocation ukuze yenze imveliso. Inkqubo ye-SN1 ibonakaliswe ngokuqulunqwa kweplani ye-carbocation ephakathi, kwaye imveliso ingabonisa umxube we-stereochemistries, into eyaziwa ngokuba yi-racemization, ngenxa yokuhlaselwa kwe-nucleophile ukusuka kumacala omabini e-carbocation ecwangcisiweyo.

Nucleophilic Addition Reactions

Ukongezwa kumaqela eCarbonyl: Xa i-sodium cyanide isabela kunye ne-aldehydes okanye i-ketones, i-cyanide ion ijolise kwi-electrophilic carbonyl carbon atom. Iqela le-carbonyl line-polarized carbon - ibhondi ye-oksijini, kunye ne-athomu ye-carbon ibe yindawo ye-electrophilic. Ukuhlaselwa kwe-ion ye-cyanide kudala ibhondi entsha ye-carbon-cyanide, kwaye i-athomu ye-oksijini yeqela le-carbonyl ifumana intlawulo embi. Kwinqanaba elilandelayo, umthombo weproton, onjengamanzi okanye i-asidi, iprotonate i-athomu ye-oksijini ukwenza i-cyanohydrin. Le mpendulo iyabuyiswa, kwaye ulungelelwaniso lunokulungelelaniswa kwimveliso ngokulawula iimeko zokusabela.

Ukongeza kwi-Imines: Kwi-reaction ye-Strecker, ukongezwa kwe-ion ye-cyanide kwi-ion ionium, eyenziwa ngokusabela kwe-aldehyde okanye i-ketone ene-ammonia, ilandela indlela yokongeza i-nucleophilic efanayo. I-ioni ithinium inomrhumo olungileyo kwi-athomu yenitrogen, yenza i-carbon atom emeleneyo ye-electrophilic. I-cyanide ion ihlasela le athom yekhabhoni, yenze ibhondi entsha yekhabhoni - cyanide kwaye ibangele ukwenziwa kwe-α - amino nitrile.

Iingqwalaselo zoKhuseleko

Kubalulekile ukugxininisa ukuba i-sodium cyanide inetyhefu kakhulu. Ukusezela umoya, ukungenwa, okanye ukudibana nolusu kungabulala. Xa usebenza ne-sodium cyanide, iiprotocol eziqinileyo zokhuseleko kufuneka zithotyelwe. Oku kuquka ukwenza imifuniselo kwindawo enomsi engena umoya, ukunxiba izixhobo ezifanelekileyo zokuzikhusela njengeeglavu, iiglavu, idyasi yelebhu, nokuba nezicwangciso ezifanelekileyo zokusabela kwimeko kaxakeka xa unokuvelelwa ngengozi.

isiphelo

Isodium cyanide sisixhobo esinamandla kwaye sisebenza ngeendlela ezininzi kwi-organic synthesis. Ukukwazi kwayo ukusebenza njenge-nucleophile kunye nokudala i-carbon entsha-ibhondi zekhabhoni iyenza ibe sisixhobo esiyimfuneko kwiikhemisti ekwenzeni uluhlu olubanzi lweekhompawundi eziphilayo. Ukuqonda iindlela zokusabela ezibandakanya i-sodium cyanide kubalulekile ekuyileni iindlela ezisebenzayo zokwenziwa kunye nokuqikelela iziphumo zokusabela. Nangona kunjalo, ngenxa yetyhefu ephezulu, ukusetyenziswa kwayo kufuneka kulawulwe ngononophelo kwaye kuqhutywe ngeyona ndlela yokhuseleko yokukhusela intlalontle yeekhemisti kunye nokusingqongileyo.