Ukusetyenziswa okuNxulubilikayo kweSodium Cyanide kwi-Organic Synthesis

intshayelelo

I-Sodium cyanide (NaCN), enefomyula yekhemikhali i-NaCN, yi-crystalline solid okanye umgubo omhlophe onyibilikayo emanzini kwaye unevumba elibi le-almond. Ngenxa yokusabela kwayo okuphezulu, ifunyenwe isetyenziswa kakhulu kwiindlela ezahlukeneyo zokwenziwa kwezinto eziphilayo . Nangona kunjalo, kubalulekile ukuqaphela ukuba i-sodium cyanide inetyhefu kakhulu kwaye kufuneka iphathwe ngononophelo olukhulu nangokuhambelana nemigaqo yokhuseleko. Eli nqaku liphonononga ukusetyenziswa okuhlukeneyo kwe- Sodium Cyanide kwi-organic synthesis.

Usetyenziso kwi-Organic Synthesis

Ukusabela kweStrecker

Enye yezona ndlela zidumileyo zokusetyenziswa kweSodium cyanide kwi-organic synthesis yiStrecker reaction. Le reaction yindlela enamandla yokwenza i-α-amino acids. KwiStrecker reaction, i-aldehyde okanye i-ketone isabela kunye ne-ammonium chloride (NH₄Cl) kunye ne-sodium cyanide. Indlela yokusebenza ngokubanzi yile ilandelayo:

1. Okokuqala, i-aldehyde okanye i-ketone idibana ne-ammonia (eyenziwe kwi-situ evela kwi-ammonium chloride) ukuze yenze i-imine. Iqela le -Carbon yl le-aldehyde okanye i-ketone liyi-protonated, nto leyo eyenza ukuba ibe yi-electrophilic ngakumbi. Emva koko, i-ammonia ihlasela i-protonated carbonyl carbon, ilandelwe yi-deprotonation ukuze yenze i-imine.

2. Emva koko, i-cyanide ion (CN⁻) evela kwi-sodium cyanide isebenza njenge-nucleophile kwaye ihlasela i-imine carbon. Oku kwenza i-α - i-amino nitrile ephakathi.

3. Ekugqibeleni, i-hydrolysis ye-α - i-amino nitrile phantsi kwe-acidic okanye iimeko ezisisiseko zivelisa i-α ehambelanayo - i-amino acid.

I-Strecker reaction ibonelela ngendlela ethe ngqo yokwazisa zombini iqela le-amino kunye neqela le-carboxyl (emva kwe-hydrolysis ye-nitrile) kwi-athomu ye-carbon enye, ebalulekileyo ekudityanisweni kwee-amino acids, iibhloko zokwakha iiprotheni. Ngokomzekelo, xa i-formaldehyde (HCHO) isabela nge-ammonium chloride kunye ne-sodium cyanide, ilandelwa yi-hydrolysis, i-glycine (NH₂CH₂COOH), i-amino acid elula, inokufumaneka.

Ukulungiswa kweeNitriles

I-sodium cyanide isetyenziswa ngokuqhelekileyo ukulungiselela i-nitriles. Kwi-substitution reaction, i-alkyl halides (efana ne-methyl bromide, i-CH₃Br) isabela nge-sodium cyanide kwi-solvent ye-polar aprotic efana ne-dimethyl sulfoxide (DMSO) okanye i-acetone. Ukusabela kuqhubeka ngendlela ye-SN2, apho i-ion ye-cyanide ihlasela i-athomu yekhabhoni ebotshelelwe kwi-halogen. I-athomu ye-halogen iyasuswa, kwaye i-alkyl nitrile yenziwa. Njengokuba:

CH₃Br + NaCN → CH₃CN + NaBr

I-Aryl nitriles inokuphinda yenziwe kusetyenziswa i-sodium cyanide kwiimeko ezithile. Ngokomzekelo, kwezinye iinguqu - i-metal-catalyzed reactions, i-aryl halides inokusabela kunye ne-sodium cyanide phambi kwe-catalyst efana ne-copper (I) cyanide (CuCN) okanye i-palladium catalysts. Le ndlela yokusabela ivumela ukwaziswa kweqela elisebenzayo le-CN kwiringi enuka kamnandi, eluncedo ekudityanisweni kwamachiza ahlukeneyo, amachiza agrogriswayo, kunye nedayi.

I-Benzoin Condensation

I-benzoin condensation yenye indlela ebalulekileyo yokusabela apho i-sodium cyanide idlala indima ebalulekileyo. Kule mpendulo, i-aldehydes enevumba elimnandi (i-aldehydes enendandatho enevumba elimnandi, efana ne-benzaldehyde, C₆H₅CHO) isabela phambi kobuninzi be-catalytic ye-sodium cyanide kwisisombululo esinxilisayo. Indlela yokusabela ibandakanya la manyathelo alandelayo:

1. I-cyanide ion iqala yongeza kwi-carbonyl carbon ye-benzaldehyde, esebenza njenge-nucleophile. Le mveliso yokongeza yicyanohydrin - efana nephakathi.

2. Umrhumo ongalunganga kwi-athomu ye-oksijini ye-cyanohydrin - njenge-intermediate inokuhlasela i-carbonyl carbon ye-benzaldehyde molekyuli.

3. Emva koluhlu lwamanyathelo okudlulisa iproton kunye nokupheliswa kwe-ion ye-cyanide, i-benzoin (α - i-hydroxy - ketone) yenziwe.

I-benzoin condensation ibonelela ngendlela yokwenza i-carbon entsha-carbon bond phakathi kweemolekyuli ezimbini ze-aldehyde, ezixabisekileyo ekuhlanganiseni iimolekyuli ze-organic eziyinkimbinkimbi. Nangona kwiminyaka yakutshanje, iinzame zenziwe zokutshintsha i-sodium cyanide kunye ne-catalysts ehambelana nokusingqongileyo njengetyuwa ye-thiazolium okanye i-vitamin B₁, indlela yendabuko yokusebenzisa i-sodium cyanide isasebenza kwezinye iimeko.

Iimpendulo ezongeziweyo kwiiNcoma ezingaxutywanga

I-sodium cyanide inokuthatha inxaxheba kwiimpendulo ezongezelelweyo kwiikhompawundi ezingaxutywanga. Ngokomzekelo, phambi kwe-catalyst, inokongeza kwi-α, β - i-unsaturated carbonyl compounds (njenge-acrolein, CH₂=CHCHO). Ukusabela kulandela uMichael - uhlobo lokudibanisa indlela, apho i-ion yecyanide ihlasela i-β - carbon ye-α,β - i-unsaturated carbonyl compound. Le mpendulo ingasetyenziselwa ukwazisa iqela le-cyanomethyl (-CH₂CN) kwi-system unsaturated, enokuthi iguqulwe ngakumbi ibe ngamanye amaqela asebenzayo. Ngokomzekelo, imveliso ephumayo inokuthi ifakwe i-hydrolyzed ukwenza i-carboxylic acid okanye iyancipha ukwenza i-amine.

Iingqwalaselo zoKhuseleko

Njengoko bekutshiwo ngaphambili, i-sodium cyanide inetyhefu kakhulu. Ukuphefumla, ukungeniswa, okanye ukudibana kwesikhumba nesodium cyanide kunokubulala. Idibana neeasidi ukuvelisa ihydrogen cyanide (HCN), irhasi enetyhefu kakhulu. Xa uphatha i-sodium cyanide, la manyathelo okhuseleko alandelayo kufuneka athotyelwe ngokungqongqo:

1. Sebenzisa kwindawo engena umoya kakuhle ukunqanda ukwakheka kweegesi eziyityhefu.

2. Nxiba izixhobo ezifanelekileyo zokuzikhusela, kuquka iiglavu, iiglasi, kunye nedyasi yelebhu. Kwezinye iimeko, kusenokufuneka isixhobo sokuphefumla.

3. Gcina i-sodium cyanide kwindawo ekhuselekileyo, ebhalwe phantsi kwi-acids kunye nezinye iikhemikhali ezisebenzayo.

4. Yiba nezicwangciso ezifanelekileyo zokusabela kwimeko yonxunguphalo kunye nezixhobo ezifanelekileyo kwimeko yokuchitheka okanye iingozi.

isiphelo

I-sodium cyanide yi-reagent eguquguqukayo kwaye ibalulekileyo kwi-organic synthesis. Ivumela ukusekwa kwamaqela ahlukeneyo asebenzayo abalulekileyo afana ne-amino acids, i-nitriles, kunye ne-α - i-hydroxy - i-ketones, kwaye ithatha inxaxheba kwi-carbon - carbon bond - ukwenza iimpendulo ezibalulekileyo. Nangona i-toxicity yayo, xa iphathwa ngononophelo olukhulu kunye nokuthotyelwa kwemimiselo yokhuseleko, iyaqhubeka iyisixhobo esibalulekileyo kwi-toolkit ye-synthetic chemist yokulungiswa koluhlu olubanzi lwee-organic compounds, ukusuka kwi-pharmaceuticals ukuya kwiikhemikhali ezintle. Nangona kunjalo, iinzame zophando eziqhubekayo zijolise ekuphuhliseni ezinye iindlela, iindlela ezikhuselekileyo zokuphumeza iinjongo ezifanayo zokwenziwa.