• Bulletin of the Korean Chemical Society
• /
• v.23 no.12
• /
• pp.1697-1698
• /
• 2002

• Bulletin of the Korean Chemical Society
• /
• v.27 no.1
• /
• pp.121-122
• /
• 2006

• Bulletin of the Korean Chemical Society
• /
• v.13 no.4
• /
• pp.451-453
• /
• 1992

• Bulletin of the Korean Chemical Society
• /
• v.14 no.2
• /
• pp.302-303
• /
• 1993

• Bulletin of the Korean Chemical Society
• /
• v.8 no.4
• /
• pp.301-304
• /
• 1987

A systematic study of the partial reduction of nitriles to the corresponding aldehydes with thexylbromoborane-methyl sulfide $(ThxBHBr{\cdot}SMe_2)$ under practical conditions has been carried out. The yields of aldehydes are good in the aliphatic series. However, the yields of aromatic series vary with substituents and ring itself.

• Bulletin of the Korean Chemical Society
• /
• v.15 no.10
• /
• pp.881-888
• /
• 1994

The approximate rates and stoichiometry of the reaction of excess sodium tris(diethylamino)aluminum hydride (ST-DEA) with selected organic compounds containing representative functional groups under standardized conditions(tetrahydrofuran, $0{\circ}$) were studied in order to characterize the reducing characteristics of the reagent for selective reductions. The reducing ability of STDEA was also compared with those of the parent sodium aluminum hydride (SAH) and lithium tris(diethylamino)aluminum hydride (LTDEA). The reagent appears to be milder than LTDEA. Nevertheless, the reducing action of STDEA is very similar to that observed previously for LTDEA, as is the case of the corresponding parent sodium and lithium aluminum hydrides. STDEA shows a unique reducing characteristics. Thus, benzyl alcohol, phenol and 1-hexanol evolved hydrogen slowly, whereas 3-hexanol and 3-ethyl-3-pentanol, secondary and tertiary alcohols, were essentially inert to STDEA. Primary amine, such as n-hexylamine, evolved only 1 equivalent of hydrogen slowly. On the other hand, thiols examined were absolutely stable. STDEA reduced aidehydes and ketones rapidly to the corresponding alcohols. The stereoselectivity in the reduction of cyclic ketones by STDEA was similar to that by LTDEA. Quinones, such as p-benzoquinone and anthraquinone, were reduced to the corresponding 1,4-dihydroxycyclohexadienes without evolution of hydrogen. Carboxylic acids and anhydrides were reduced very slowly, whereas acid chlorides were reduced to the corresponding alcohols readily. Esters and epoxides were also reduced readily. Primary carboxamides consumed hydrides for reduction slowly with concurrent hydrogen evolution, but tertiary amides were readily reduced to the corresponding tertiary amines. The rate of reduction of aromatic nitriles was much faster than that of aliphatic nitriles. Nitrogen compounds examined were also reduced slowly. Finally, disulfide, sulfoxide, sulfone, and cyclohexyl tosylate were readily reduced without evolution of hydrogen. In addition to that, the reagent appears to be an excellent partial reducing agent: like LTDEA, STDEA converted ester and primary carboxamides to the corresponding aldehydes in good yields. Furthermore, the reagent reduced aromatic nitriles to the corresponding aldehydes chemoselectively in the presence of aliphatic nitriles. Consequently, STDEA can replace LTDEA effectively, with a higher selectivity, in most organic reductions.

• Applied Chemistry for Engineering
• /
• v.26 no.2
• /
• pp.128-131
• /
• 2015

Hydration of nitriles in the environmentally benign neutral conditions is the most economical and attractive way to produce amides. Substantial research works have been carried out to apply the solid metal oxides and transition metal supported catalytic systems to promote the hydration of nitriles. The most significant feature of these catalysts is the applicability to a wide range of substrates including aromatic, alicyclic, hetero-atomic, and aliphatic nitriles. These catalysts are also characterized by the easy isolation from the reaction mixture and the reusability while maintaining the high catalytic activity. This review accounts over the detailed survey of the metal oxide and solid supported metal catalysts for preparing amides from the hydration of nitriles.

• Bulletin of the Korean Chemical Society
• /
• v.10 no.1
• /
• pp.75-80
• /
• 1989

The approximate rates and stoichiometry of the reaction of excess potassium 9-sec-amyl-9-boratabicylco[3.3.1]nonane (K 9-sec-Am-9-BBNH) with selected organic compounds containing representative functional goups under standardized conditions (tetrahydrofuran, $0^{\circ}C)$ were examined in order to explore the reducing characteristics of the reagent for selective reductions. The reagent readily reduces aldehydes, ketones, acid chlorides and epoxides to the corresponding alcohols. However, carboxylic acid, aliphatic nitriles, t-amides, and some sulfur compounds show very little reactivity or no reactivity to this reagent. The most interesting feature of the reagent is that aromatic nitriles are reduced moderately to the corresponding aldehyde stage, wheras aliphatic nitriles are inert. In addition, the reagent shows a high stereoselectivity toward cyclic ketones at $0^{\circ}C$ and - $25^{\circ}C.$ The selectivity exhibited at $0^{\circ}C$ is comparable to that by lithium trisiamylborohydride at that temperature.

• Bulletin of the Korean Chemical Society
• /
• v.14 no.6
• /
• pp.743-749
• /
• 1993

The approximate rates and stoichiometry of the reaction of excess lithium tris(dihexylamino)aluminum hydride(LTDHA) with selected organic compounds containing representative functional groups under the standardized conditions (tetrahydrofuran, 0$^{\circ}$C) were studied in order to define the reducing characteristics of the reagent for selective reductions. The reducing ability of LTDHA was also compared with those of the parent lithium aluminum hydride(LAH), lithium tris(diethylamino)aluminum hydride(LTDEA), and lithium tris(dibutylamino)aluminum hydride(LTDBA). In general, the reactivity toward organic functionalities is in order of $LAH{\gg}LTDEA{\geq}LTDBA>LTDHA$. LTDHA shows a unique reducing characteristics. Thus, the reagent reduces aldehydes, ketones, esters, epoxides, and tertiary amides readily. Anthraquinone is cleanly reduced to 9,10-dihydro-9,10-anthracenediol without hydrogen evolution, whereas p-benzoquinone in inert to LTDHA. In addition to that, disulfides are also readily reduced to thiols without hydrogen evolution. However, carboxylic acids, anhydrides, nitriles, and primary amides are reduced slowly. Especially, this reagent reduces aromatic nitriles to the corresponding aldehydes in good yields.

• Bulletin of the Korean Chemical Society
• /
• v.13 no.6
• /
• pp.670-676
• /
• 1992

A systematic study of the partial reduction of carboxylic acids and their derivatives to the corresponding aldehydes with lithium tris(dialkylamino)aluminum hydrides under practical conditions has been carried out. The diethylaminosubstituted derivative of lithium aluminum hydride, lithium tris(diethylamino)aluminum hydride (LTDEA), shows quite general applicability in the conversion of carboxylic acids, carboxylic esters, and primary carboxamides to the corresponding aldehydes. Lithium tripiperidinoaluminum hydride (LTPDA) also appears to be a reagent of choice for such partial transformation of primary carboxamides. In additioin, both LTDEA and LTPDA reduce tertiary carboxyamides to aldehydes in high yields. Finally, lithium tris(dihexylamino)aluminum hydride (LTDHA) is capable of achieving the chemoselective reduction of aromatic nitriles to aldehydes in the presence of aliphatic nitriles under practical conditions.