15205-15-9Relevant articles and documents
Reaction of Diisobutylaluminum Borohydride, a Binary Hydride, with Selected Organic Compounds Containing Representative Functional Groups
Amberchan, Gabriella,Snelling, Rachel A.,Moya, Enrique,Landi, Madison,Lutz, Kyle,Gatihi, Roxanne,Singaram, Bakthan
supporting information, p. 6207 - 6227 (2021/05/06)
The binary hydride, diisobutylaluminum borohydride [(iBu)2AlBH4], synthesized from diisobutylaluminum hydride (DIBAL) and borane dimethyl sulfide (BMS) has shown great potential in reducing a variety of organic functional groups. This unique binary hydride, (iBu)2AlBH4, is readily synthesized, versatile, and simple to use. Aldehydes, ketones, esters, and epoxides are reduced very fast to the corresponding alcohols in essentially quantitative yields. This binary hydride can reduce tertiary amides rapidly to the corresponding amines at 25 °C in an efficient manner. Furthermore, nitriles are converted into the corresponding amines in essentially quantitative yields. These reactions occur under ambient conditions and are completed in an hour or less. The reduction products are isolated through a simple acid-base extraction and without the use of column chromatography. Further investigation showed that (iBu)2AlBH4 has the potential to be a selective hydride donor as shown through a series of competitive reactions. Similarities and differences between (iBu)2AlBH4, DIBAL, and BMS are discussed.
Reaction of InCl3 with various reducing agents: InCl 3-NaBH4-mediated reduction of aromatic and aliphatic nitriles to primary amines
Saavedra, Jaime Z.,Resendez, Angel,Rovira, Alexander,Eagon, Scott,Haddenham, Dustin,Singaram, Bakthan
experimental part, p. 221 - 228 (2012/02/05)
While alternative methods of preparing dichloroindium hydride (HInCl 2) via the in situ reduction of InCl3 using lithium amino borohydride (LAB) were explored, generation of HInCl2 from the reduction of InCl3 by sodium borohydride (NaBH4) was also re-evaluated for comparison. The reductive capability of the InCl 3/NaBH4 system was found to be highly dependent on the solvent used. Investigation by 11B NMR spectroscopic analyses indicated that the reaction of InCl3 with NaBH4 in THF generates HInCl2 along with borane-tetrahydrofuran (BH 3?THF) in situ. Nitriles underwent reduction to primary amines under optimized conditions at 25 °C using 1 equiv of anhydrous InCl 3 with 3 equiv of NaBH4 in THF. A variety of aromatic, heteroaromatic, and aliphatic nitriles were reduced to their corresponding primary amine in 70-99% isolated yields. Alkyl halide and nitrile functional groups were reduced in tandem by utilizing the reductive capabilities of both HInCl2 and BH3?THF in a one-pot reaction. Finally, the selective reduction of the carbon bromine bond in the presence of nitriles was achieved by generating HInCl2 via the reduction InCl3 with NaBH4 in CH3CN or with lithium dimethylaminoborohydride (MeLAB) in THF.
Lithium aminoborohydrides 16. Synthesis and reactions of monomeric and dimeric aminoboranes
Pasumansky, Lubov,Haddenham, Dustin,Clary, Jacob W.,Fisher, Gary B.,Goralski, Christian T.,Singaram, Bakthan
, p. 1898 - 1905 (2008/09/18)
(Chemical Equation Presented) Aminoboranes are synthesized in situ from the reaction of the corresponding lithium aminoborohydrides (LABs) with methyl iodide, trimethylsilylchloride (TMS-Cl), or benzyl chloride under ambient conditions. In hexanes, the reaction using methyl iodide produces aminoborane and methane, whereas in tetrahydrofuran (THF) this reaction produces amine-boranes (R1R2HN:BH3) as the major product. The reaction of iPr-LAB with TMS-Cl or benzyl chloride yields exclusively diisopropylaminoborane [BH2-N(iPr)2] in THF as well as in hexanes at 25°C. Diisopropylaminoborane and dicyclohexylaminoborane exist as monomers due to the steric requirement of the alkyl group. All other aminoboranes studied are not sterically hindered enough to be monomers in solution, but instead exist as a mixture of monomers and dimers. The dimers are four-membered rings formed through boron-nitrogen coordination. In general aminoboranes are not hydroborating reagents. However, monomelic aminoboranes, such as BH2-N(iPr)2, can reduce nitriles in the presence of catalytic amounts of LiBH4. This BH 2-N(iPr)2/LiBH4 reducing system also reduces ketones, aldehydes, and esters. Diisopropylaminoborane, synthesized from iPr-LAB, can be converted into boronic acids by a palladium-catalyzed reaction with aryl bromides. Aminoboranes derived from heterocyclic amines, such as pyrrole, pyrazole, and imidazole, can be prepared by the direct reaction of borane/tetrahydrofuran (BH3:THF) with these heterocyclic amines. It has been reported that pyrazole-derived aminoborane forms a six-membered dimer through boron-nitrogen coordination, where as, pyrrolylborane forms a dimer through boron-hydrogen coordination. Pyrrolylborane monohydroborates both alkenes and alkynes at ambient temperatures. Hydroboration of styrene with pyrrolylborane followed by hydrolysis gives the corresponding boronic acid, 2-phenylethylboronic acid, in 40% yield. Similarly phenylacetylene is mono-hydroborated by pyrrolylborane, to give E-2-phenylethenylboronic acid in 50% yield.