- Reductive dechlorination of BCl3 for efficient ammonia borane regeneration
-
This paper reports a complete ammonia borane (AB) regeneration process in which Bu3SnH was utilized as a reductant for the reductive dechlorination of BCl3, and Et2PhN was selected as a 'helper ligand' to generate Et2PhN·BH3, which gives rise to a high yield of AB by a base-exchange reaction at ambient temperature.
- Tan, Yingbin,Zhang, Lijun,Chen, Xiaowei,Yu, Xuebin
-
supporting information
p. 753 - 757
(2015/02/19)
-
- Corey-itsuno reduction of ketones: A development of safe and inexpensive process for synthesis of some API intermediates
-
A safe and inexpensive procedure for asymmetric reduction of ketones using in situ prepared N,N-diethylaniline borane (DEANB) and oxazaborolidine catalyst from sodium borohydride, N,N-diethylaniline hydrochloride and (S)-α,α-diphenylprolinol is described. This protocol is demonstrated successfully to manufacture enantiopure dapoxetine at the plant scale.
- Mahale, Rajendra D.,Chaskar, Sudhir P.,Patil, Kiran E.,Maikap, Golak C.,Gurjar, Mukund K.
-
experimental part
p. 710 - 713
(2012/07/27)
-
- A SIMPLE CONVENIENT METHOD FOR THE GENERATION OF DIBORANE FROM NaBH4 AND I2
-
Treatment of NaBH4 with I2 in diglyme yields diborane which can be utilized conveniently for the preparation of a borane-N,N-diethylaniline complex and other borane-Lewis base complexes.
- Narayana, C.,Periasamy, M.
-
p. 145 - 148
(2007/10/02)
-
- Molecular addition compounds. 9. Effect of structure on the reactivities of representative borane-amine complexes in typical reactions such as hydrolysis, hydroboration, and reduction
-
A number of borane-amine complexes with widely different structural features in the amine portion was prepared and their reactivities toward typical B-H reactions, such as hydrolysis, hydroboration of 1-octene, and reduction of cyclohexanone, were studied. BH3-amine complexes containing an N-phenyl group are hydrolyzed by neutral hydroxylic solvents, while others require a strong acid medium for the hydrolysis. In hydroboration, BH3-N-phenylamine complexes react rapidly with 1-octene in THF at 25°C, while all other types require refluxing THF or toluene for reaction. Again, BH3-N-phenylamine complexes reduce cyclohexanone in THF at 25°C at reasonable rates, while others require acetic acid solvent or mineral or Lewis acids to achieve the desired reduction. Thus, among such borane-amine addition compounds, the BH3-N-phenylamines emerge as unique hydroborating and reducing agents. The results of the present study provide insights into the mechanisms of the hydroboration and reduction reactions. The rates of hydroboration of alkenes with BH3-amine complexes are inversely related to the stability of the adduct, arguing for a prior dissociation of the adduct, followed by the reaction of BH3 with the alkene. The reduction of cyclohexanone with BH3-amine complex in THF proceeds by an analogous dissociation mechanism. In acetic acid or in the presence of mineral or Lewis acids, a bimolecular attack of the BH3-amine complex on the protonated carbonyl group has been considered to be the most viable mechanistic pathway. However, this does not account for the effect of acids on hydrolytic behavior. Consequently, caution is urged in considering possible interpretation of the acid-enhanced reactions of amine-boranes.
- Brown, Herbert C.,Murray, Leo T.
-
p. 2746 - 2753
(2008/10/08)
-