ʻO ke kuleana a me nā hana o Sodium Cyanide i ka Organic Synthesis

Introduction

ʻO Sodium Cyanide (NaCN), kahi mea paʻa kristal keʻokeʻo i hoʻoheheʻe maikaʻi ʻia i ka wai, he kumu ikaika a he nucleophile ikaika hoʻi, e lilo ia i mea waiwai nui i ka synthesis Organic . ʻOiai kona ʻawahia nui, kahi e pono ai nā hana palekana koʻikoʻi i ka wā e lawelawe ai, he kuleana koʻikoʻi ko Sodium cyanide i ka synthesis o nā hui organik like ʻole, me nā lāʻau lapaʻau, nā agrochemicals, a me nā polymers.

Ke kuleana o Sodium Cyanide i ka Organic Synthesis

ʻO Cyanide Ion ma ke ʻano he Nucleophile

He nucleophile reactive loa ka ion cyanide i loko o ka Sodium Cyanide . Mahalo i ka hoʻopiʻi maikaʻi ʻole ma ka ʻātoma Carbon a me ke electronegativity kiʻekiʻe o ka ʻātoma nitrogen, hiki iā ia ke hoʻouka i nā kikowaena electrophilic i loko o nā molekala organik, e like me nā hui carbonyl, alkyl halides, a me nā epoxides.

Hoʻokumu ʻana i nā Paʻa C - C

ʻO kekahi o nā hana koʻikoʻi o ka sodium cyanide i ka synthesis organik ʻo ia ka hoʻokumu ʻana i nā pilina kalapona - kalapona hou, i hoʻokō ʻia ma o ka hoʻololi nucleophilic a me nā hopena hoʻohui. No ka laʻana, ke hana ka alkyl halide me ka sodium cyanide, pani ka ion cyanide i ka ion halide, e alakaʻi ana i ka hoʻokumu ʻana o kahi nitrile. Hāʻawi kēia hopena i kahi ala maʻalahi e hoʻokomo i kahi ʻātoma kalapona hou i loko o ka mole. Ma hope mai, hiki ke hoʻololi ʻia ka hui nitrile i nā hui hana ʻē aʻe e like me nā waikawa carboxylic, amines, a i ʻole aldehydes ma o nā kaʻina hana kemika like ʻole.

Hoʻohui ʻia o nā ʻakika Amino - ʻO ka Strecker Reaction

ʻO ka sodium cyanide kahi mea nui i ka hopena Strecker, i hoʻohana ʻia no ka synthesis o α - amino acids. Ma kēia pane ʻana, hui pū kekahi aldehyde a i ʻole ketone me ka ammonium chloride a me ka sodium cyanide e hana i kahi α - amino nitrile. Hiki ke hydrolyzed kēia α - amino nitrile e hana i ka α - amino acid.

Hoʻomaka ka hopena ma nā ʻanuʻu he nui: ʻO ka mua, ʻo ka hui carbonyl o ka aldehyde a i ʻole ketone e hana i ka protonation, e hoʻonui ana i kona electrophilicity. A laila, hoʻouka kekahi mole ammonia i ka pūʻulu carbonyl protonated, a ukali ʻia e ka deprotonation e hana i kahi hemiaminal. ʻO ka hope aʻe, ua hoʻoneʻe ʻia ka pūʻulu hydroxyl o ka hemiaminal, ka hopena i ka hoʻopau ʻana i ka wai a me ka hoʻokumu ʻana o kahi ion iminium. Hoʻouka ka cyanide ion i ka ion iminium e hāʻawi i ka α - amino nitrile. ʻO ka hope, hāʻawi ka hydrolysis o ka α - amino nitrile i mua o kahi waikawa a i ʻole kahi kumu i hāʻawi i ka α - amino acid.

Synthesis of Nitriles from Aryl Halides - The Rosenmund - von Braun Reaction

Ma ka hopena Rosenmund - von Braun, hoʻohana ʻia ka sodium cyanide e hoʻololi i nā aryl halides, ʻo ia nā mea halogen - i hoʻololi ʻia i nā mea ʻala, i nā nitriles aril. Hoʻopili ʻia e ka copper(I) cyanide a koi pinepine i nā wela kiʻekiʻe, pili kēia pane i ka hoʻokumu ʻana o ke keleawe - aryl intermediate. Hoʻopili ka cyanide ion mai ka sodium cyanide me kēia waena e hana i ka aryl nitrile. He mea nui kēia kaʻina hana no ka hoʻokomo ʻana i kahi pūʻulu hana nitrile ma luna o ke apo ʻala, hiki ke hoʻololi hou ʻia no ka synthesis o nā pūhui ʻala like ʻole, e like me nā lāʻau lapaʻau a me nā mea pena.

ʻO ka hoʻohui ʻana o nā hui carbonyl

Hoʻokomo pū ka sodium cyanide i ka synthesis o nā pūhui carbonyl. No ka laʻana, ke hana ʻo ia me kahi epoxide, hoʻouka ka cyanide ion i ka ʻātoma kalapona liʻiliʻi i hoʻololi ʻia o ke apo epoxide, e wehe ai ke apo. Hiki i ka hydrolysis o ka cyanohydrin hopena ke alakaʻi i ka hoʻokumu ʻana o kahi pūhui carbonyl.

Mechanisms of Reactions Involving Sodium Cyanide

Nucleophilic Substitution Reactions

ʻAno Hana SN2 : Ke hana ka sodium cyanide me nā alkyl halides mua, ma muli o ka hana ʻana o ka sodium cyanide i kahi ʻano hana SN2 (bimolecular nucleophilic substitution). Hoʻouka ka ion cyanide i ka ʻātoma kalapona i hoʻopili ʻia i ka halogen mai ke kua, e kūʻē ana i ke kūlana o ka ion halide haʻalele. He hana hui pū kēia kahi e haki ai ka pilina kalapona - halogen a me ka hoʻokumu ʻana o ka pilina kalapona - cyanide i ka manawa like. Aia ka wikiwiki o ka hana ʻana ma luna o nā ʻano o ka alkyl halide a me ka ion cyanide, a ua hoʻohuli ʻia ke ʻano stereochemistry o ka huahana i hoʻohālikelike ʻia me ka mea hoʻomaka.

ʻAno Hana SN1 : Me nā alkyl halides tertiary, hiki ke hoʻomau ʻia ka hopena ma o kahi ʻano hana SN1 (unimolecular nucleophilic substitution). ʻO ka mea mua, hoʻokaʻawale ka alkyl halide e hana i kahi waena carbocation. A laila, hoʻouka ka ion cyanide i kēia carbocation e hana i ka huahana. Hōʻike ʻia ka ʻano hana SN1 e ka hoʻokumu ʻana o kahi waena carbocation planar, a hiki i ka huahana ke hōʻike i kahi hui ʻana o nā stereochemistries, kahi hanana i ʻike ʻia ʻo racemization, ma muli o ka hoʻouka ʻana o ka nucleophile mai nā ʻaoʻao ʻelua o ka planar carbocation.

Nucleophilic Pākuʻi Reaction

Hoʻohui i nā Hui Carbonyl : Ke hana ka sodium cyanide me nā aldehydes a i ʻole ketones, kuhikuhi ka ion cyanide i ka ʻātoma carbonyl electrophilic. Loaʻa i ka hui carbonyl kahi pilina carbon-oxygen polarized, me ka ʻātoma carbon ka wahi electrophilic. ʻO ka hoʻouka ʻana o ka ion cyanide e hana i kahi pilina carbon-cyanide hou, a loaʻa i ka ʻātoma oxygen o ka hui carbonyl kahi uku maikaʻi ʻole. I ka hana aʻe, kahi kumu proton, e like me ka wai a i ʻole ka waikawa, e protonates i ka ʻātoma oxygen e hana i kahi cyanohydrin. Hiki ke hoʻohuli ʻia kēia hana, a hiki ke hoʻoponopono ʻia ke kaulike i ka huahana ma ka kaohi ʻana i nā kūlana hana.

Hoʻohui i nā Imines : I ka hopena Strecker, ʻo ka hoʻohui ʻana o ka ion cyanide i ka ion iminium, i hana ʻia mai ka hopena o kahi aldehyde a i ʻole ketone me ka ammonia, e hahai ana i kahi ʻano hoʻohui nucleophilic like. Loaʻa i ka ion iminium kahi uku maikaʻi ma ka ʻātoma nitrogen, e hana ana i ka ʻātoma kalapona e pili ana i electrophilic. Hoʻouka ka ion cyanide i kēia ʻātoma kalapona, e hana ana i kahi pilina kalapona - cyanide hou a hopena i ka hoʻokumu ʻia ʻana o kahi α - amino nitrile.

Hoʻomaopopo i ka palekana

He mea koʻikoʻi ka hoʻomaopopo ʻana he mea ʻawaʻawa loa ka sodium cyanide. Hiki ke make ka inhalation, ingestion, a i ʻole ka ʻili. I ka hana ʻana me ka sodium cyanide, pono e mālama pono i nā protocol palekana. Hoʻopili kēia i ka hana ʻana i nā hoʻokolohua i loko o kahi puʻupuʻu ua hoʻoheheʻe maikaʻi ʻia, ke ʻaʻahu ʻana i nā lako pale pilikino kūpono e like me nā mīkina lima, nā maka aniani, a me ka ʻaʻahu lab, a me ka loaʻa ʻana o nā hoʻolālā pane ulia pōpilikia ma kahi o ka hōʻike ʻana.

Panina

ʻO ka sodium cyanide kahi reagent ikaika a maʻalahi i ka synthesis organik. ʻO kona hiki ke hana ma ke ʻano he nucleophile a hana i nā paʻa kalapona hou - he mea pono loa ia no ka poʻe chemists i ka synthesizing i kahi ākea o nā pūhui organik. He mea nui ka hoʻomaopopo ʻana i nā ʻano hana e pili ana i ka sodium cyanide no ka hoʻolālā ʻana i nā ala synthetic kūpono a me ka wānana i nā hopena hopena. Eia nō naʻe, ma muli o kona ʻona kiʻekiʻe, pono e hoʻoponopono maikaʻi ʻia ka hoʻohana ʻana a mālama ʻia me ka palekana palekana loa e mālama i ke ola o nā chemists a me ke kaiapuni.