Reaction of Representative Organic Compounds with Sodium Borohydride in the Presence of Aluminum Chloride

윤능민,이호준,정진순,Yoon Nung Min,Ho Jun Leeq,Jin Soon Chung Korean Chemical Society 1973 대한화학회지 Vol.17 No.4

유기화합물의 선택환원에 필요한 자료를 얻기 위하여 수소화붕소나트륨과 염화알루미늄의 3:1 혼합물의 테트라히드로푸란 용액에서의 환원성을 규명하였다. 49개의 대표적 유기화합물을 골라 이시약과 실온에서 작용하여 대략의 반응속도와 정량관계를 알아보았다. 테트라히드로푸란 용액에서 염화알루미늄 1몰에 수소화붕소나트륨 3몰을 가하면 현탁용액이 생기는데 수소화붕소나트륨 보다는 훨씬 환원성이 강하다. 알데히드와 케톤은 한시간 이내에 빨리 환원되고 아실유도체는 서서히 그러나 카르복시산은 매우 느리게 환원되었다. 에스테르, 락톤, 에폭시드는 수소화붕소나트륨이나 보란보다 훨씬 빨리 환원되었다. 삼차 아미드는 서서히 환원되었으나 일차 아미드는 수소는 발생하지만 환원은 거의 일어나지 않았다. 벤조니트릴은 30분에 환원이 완결되었으나 카프로니트릴은 느리게 환원되었다. 니트로화합물, 이황화물, 술폰등은 이 시약과 반응하지 않으나 아조, 아족시, 옥심기는 서서히 반응하고 이소시안산페닐은 도중단계까지만 환원되었다 올레핀은 쉽게 수소화붕소화 반응을 하였다. The addition of one mole of aluminum chloride to three moles of sodium borohydride in tetrahydrofuran gives a turbid solution with enormously more powerful reducing properties than those of sodium borohydride itself. The reducing properties of this reagent were tested with 49 organic compounds which have representative functional groups. Alcohols liberated hydrogen immediately but showed no sign of hydrogenolysis of alkoxy group. Aldehydes and ketones were reduced rapidly within one hr. Acyl derivatives were reduced moderately, however, carboxylic acids were reduced much more slowly. Esters, lactones and epoxides were reduced readily than sodium borohydride or borane. Tertiary amide was reduced slowly, however, primary amide consumed one hydride for hydrogen evolution but reduction was sluggish. Aromatic nitrile was reduced much more readily than aliphatic nitrile. Nitro compounds were inert to this reagent but azo and azoxy groups were slowly attacked. Oxime was reduced slowly but isocyanate was only partially reduced. Disulfide and sulfoxide were attacked slowly but sulfide and sulfone were inert. Olefin was hydroborated rapidly.

Reductions of Some Representative Organic Compounds with $NaBH_4-(C_6H_5O)_3B$ System

윤능민,조병태,유지욱,김근풍,Nung Min Yoon,Byung Tae Cho,Ji Uk Yoo,Gun Poong Kim Korean Chemical Society 1983 대한화학회지 Vol.27 No.6

테트라히드로프란 용액에서 수소화붕소나트륨과 붕산트리페닐을 사용해서 카르복시산, 카르복시산염, 3차아미드 및 술폭시드를 환원하는 새로운 방법을 개발하였다. 즉 카르복시산은 실온에서 6~12시간에 정량적으로 환원될 수 있으며, 지방족 카르복시산염은 실온에서 6시간에 정량적으로 환원되나 방향족 산염은 $65^{\circ}C$에서 24시간이 소요되었다. 3차 아미드는 실온에서 3~6시간에 88∼100%의 좋은 수율로 환원되었으며, 조사한 대부분의 술폭시드는 실온에서 1~6시간에 98∼100%의 수율로 환원되었으나, 디페닐술폭시드는 보다 격렬한 조건에서 48시간에 환원할 수 있었다. New procedures for the reduction of carboxylic acids, carboxylic acid salts, tertiary amides, and sulfoxides with sodium borohydride and triphenyl borate in tetrahydrofuran were developed. Thus carboxylic acids were reduced quantitatively in 6∼12 h at $25^{\circ}C$. Alphatic acid salts were quantitatively reduced to the corresponding alcohols in 6h at $25^{\circ}C$ whereas aromatic acid salts required 24h at $65^{\circ}C$. Tertiary amides were reduced to the corresponding amines in 88∼100% yields in 3∼6h at room temperature. Most sulfoxides examined were reduced to the corresponding sulfides in 98∼100% yields in 1∼6h at $25^{\circ}C$ and completely reduced at $65^{\circ}C$; however, diphenyl sulfoxide required 48h in a more vigorous condition.

Selective Reduction with Lithium Borohydride. Reaction of Lithium Borohydride with Selected Organic Compounds Containing Representative Functional Groups

윤능민,차진순,Nung Min Yoon,Jin Soon Cha Korean Chemical Society 1977 대한화학회지 Vol.21 No.2

수소화붕소리튬-테트라히드로푸란용액의 환원특성에 대한 계통적인 연구가 52가지의 대표적인 작용기를 가진 유기화합물을 가지고 표준조건($0^{\circ}$, 테트라히드로 푸란)에서 대략의 반응속도 및 정량 관계를 알아봄으로서 이루어 졌다. The approximate rates and stoichiometries of the reaction of lithium borohydride, with fifty two selected organic compounds containing representative functional groups under the standard condition (tetrahydrofuran, $0^{\circ}$), were studied.Among the active hydrogen compounds,primary alcohols and compounds containing an acidic proton liberated hydrogen relatively fast, but secondary and tertiary alcohols very sluggishly. All the carbonyl compounds examined were reduced rapidly within one hour. Especially, among the ${\alpha}{\beta}$-unsaturated carbonyl compounds tested, the aldehydes consumed one hydride cleanly, however the cyclic ketones consumed more than one hydride even at $-20^{\circ}$. Carboxylic acids were reduced very slowly, showing about 60% reduction in 6 days at $25^{\circ}$, however acyl chlorides reduced immediately within 30 minutes. On the other hand, the reductions of cyclic anhydrides proceeded moderately to the hydroxy acid stage, however the further reductions were very slow. Aromatic and aliphatic esters, with exception of the relatively moderate reduction of acetate, were reduced very slowly, however lactones were reduced at a moderate rate. Epoxides reacted slowly, but amides and nitriles as well as the nitro compounds were all inert to this reagent. And cyclohexanone oxime and phenyl isocyanate were reduced very sluggishly. Last of all, all sulfur compounds studied were inert to this hydride.

Selective Reduction with Zinc Borohydride. Reaction of Zinc Borohydride with Selected Organic Compounds Containing Representative Functional Groups

윤능민,이호준,김혜규,강재효,Yoon Nung Min,Ho Jun Lee,Hye Kyu Kim,Jahyo Kang Korean Chemical Society 1976 대한화학회지 Vol.20 No.1

수소화붕소아연의 선택환원성을 조사하기 위하여 대표적 유기화합물 54종을 택하여 수소화붕소 아연과 일정한 조건 (THF 용액, 실온, 수소화이온의 농도 : 0.5M, 유기화합물의 농도 : 0.125M)하에서 반응시켜 대략의 반응속도와 정량관계를 알아보았다. The addition of one mole of zinc chloride to 2.33 moles of sodium borohydride in tetrahydrofuran at room temperature gave a clear chloride-free supernatant solution of zinc borohydride after stirring three days and standing at room temperature.The approximate rates and stoichiometry of the reaction of zinc borohydride with 54 selected organic compounds were determined in order to test the utility of the reagent as a selective reducing agent. Aldehydes and ketones were reduced rapidly, aromatic ketones being somewhat slowly, and the double bond of cinnamaldehyde was not attacked. Acyl halides were reduced rapidly within one hour, but acid anhydrides were reduced at a moderate rate. Carboxylic acids, both aliphatic and aromatic, were slowly reduced to alcoholic stage. Esters were inert to this reagent but a cyclic ester, γ-butyrolactone, was slowly attacked. Primary amides were reduced slowly with partial evolution of hydrogen, whereas tertiary amides underwent neither reduction nor hydrogen evolution. Epoxides and nitriles were all inert, as well as nitro, azo, and azoxy compounds. Cyclohexanone oxime and phenyl isocyanate were reduced slowly but pyridine was inert. Disulfide, sulfoxide, sulfone and sulfonic acids were stable to this reagent.

Selective Reduction of Carbonyl Compounds with Lithium Borohydride, Borane, and Borane-Lithium Chloride (1 : 0.1) in Tetrahydrofuran

윤능민,차진순,Nung Min Yoon,Jin Soon Cha Korean Chemical Society 1978 대한화학회지 Vol.22 No.4

수소화붕소리튬, 보란 그리고 보란-염화리튬(1:0.1)의 카르보닐화합물 환원에 있어서의 선택성을 5쌍의 대표적인 카르보닐화합물 쌍(벤즈알데히드-아세토페논, 벤즈알데히드-2-헵탄온, 2-헵탄온-벤조페논, 아세토페논-벤조페논, 2-헵탄온-아세토페논)에 대해서 이들 수소화물의 제한된 양을 반응시켜 알아보았다. 이들 수소화물중 보란-염화리튬(1:0.1)이 제일 선택성이 좋았고, 수소화붕소 리튬과 보란도 2-헵탄온-아세토페논 쌍을 제외하고는 좋은 선택성을 보였다. In order to find out the selective reducing characteristics of lithium borohydride, borane, and borane-lithium chloride (1 : 0.1) in the reduction of carbonyl compounds, five representative equimolar mixtures of carbonyl compounds were chosen; benzaldehyde-acetophenone, benzaldehyde-2-heptanone, 2-heptanone-benzophenone, acetophenone-benzophenone, and 2-heptanone-acetophenone, and reacted with limited amount of lithium borohydride, borane or borane-lithium chloride (1 : 0.1) in tetrahydrofuran (THF) at $0^{\circ}$. Borane-lithium chloride (1 : 0.1) showed the excellent selectivity, however, lithium borohydride and borane also exhibited good selectivity except for the 2-heptanone-acetophenone.

Selective Reduction of Keto Esters with Zinc Borohydride

윤능민,강재효,Nung Min Yoon,Jahyo Kang Korean Chemical Society 1975 대한화학회지 Vol.19 No.5

대표적 케토에스테르를 수소화붕소아연으로 선택환원하여 해당하는 히드록시에스테르 또는 락톤을 좋은 수득률로 합성하였다. Selective reduction of carbonyl group with zinc borohydride in the presence of ester functional group was demonstrated with seven representative keto esters. Either hydroxy esters or lactones were obtained in good yields; ethyl 6-hydroxyheptanoate ($83.0{\%}$), ethyl 2,6-dimethyl-4-hydroxy-2-cyclohexenecarboxylate ($82.3{\%}$), ethyl p-(${\alpha}$-hydroxyethyl)-phenylacetate ($78.9 {\%}$), 4-phenylbutyrolactone ($70.2{\%}$), and 3-phenylphthalide ($92.4{\%}$) were obtained from the corresponding keto esters.

Zinc Borohydride Reduction of ${\alpha},{\beta}$-Unsaturated Aldehydes and Ketones

윤능민,이호준,강재효,정진순,Nung Min Yoon,Ho Jun Lee,Jahyo Kang,Jin Soon Chung Korean Chemical Society 1975 대한화학회지 Vol.19 No.6

Selective Reduction of <TX>${\alpha},\;[\beta}$-Epoxy Ketones with Zinc Borohydride

윤능민,강재효,Nung Min Yoon,Jahyo Kang Korean Chemical Society 1975 대한화학회지 Vol.19 No.5

에폭시케톤을 수소화붕소 아연으로 환원하면 카르보닐기만 선택적으로 확원되어 해당하는 에폭시알코올을 좋은 수득율로 얻을수 있음을 알 수 있었다. Reduction of epoxy ketones with zinc borohydride proceeds selectively to the corresponding epoxy alcohols in good yields. Thus we obtained 3,4-epoxy-4-methyl-2-pentanol($79.8{\%}$), trans-isophorol oxide ($89.5{\%}$), trans-2-benzal-cyclohexanol oxide ($84.1{\%}$) and trans-chalcol oxide ($97.9{\%}$, crude) from the corresponding epoxy ketones.

Selective Reduction of α, β-Epoxy Ketones with Zinc Borohydride

윤능민(Nung Min Yoon),강재효(Jahyo Kang) 대한화학회 1975 대한화학회지 Vol.19 No.5

Selective Reduction of Keto Esters with Zinc Borohydride

윤능민(Nung Min Yoon),강재효(Jahyo Kang) 대한화학회 1975 대한화학회지 Vol.19 No.5