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.
Dual inhibitors of LSD1 and spermine oxidase
Holshouser, Steven,Dunworth, Matthew,Murray-Stewart, Tracy,Peterson, Yuri K.,Burger, Pieter,Kirkpatrick, Joy,Chen, Huan-Huan,Casero, Robert A.,Woster, Patrick M.
, p. 778 - 790 (2019/05/29)
We have previously described the synthesis and evaluation of 3,5-diamino-1,2,4-triazole analogues as inhibitors of the flavin-dependent histone demethylase LSD1. These compounds are potent inhibitors of LSD1 without activity against monoamine oxidases A and B, and promote the elevation of H3K4me2 levels in tumor cells in vitro. We now report that the cytotoxicity of these analogues in pancreatic tumor cells correlates with the overexpression of LSD1 in each tumor type. In addition, we show that a subset of these 3,5-diamino-1,2,4-triazole analogues inhibit a related flavin-dependent oxidase, the polyamine catabolic enzyme spermine oxidase (SMOX) in vitro.
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.
Reductions of aliphatic and aromatic nitriles to primary amines with diisopropylaminoborane
Haddenham, Dustin,Pasumansky, Lubov,DeSoto, Jamie,Eagon, Scott,Singaram, Bakthan
supporting information; experimental part, p. 1964 - 1970 (2009/07/01)
Diisopropylaminoborane [BH2Nf)Pr)2] in the presence of a catalytic amount of lithium borohydride (LiBH4) reduces a large variety of aliphatic and aromatic nitriles in excellent yields. BH 2NOPr)2 can be prepared by two methods: first by reacting diisopropylamineborane [(iPr)2N)BH3] with 1.1 equiv of n-butylhthium (n-BuLi) followed by methyl iodide (MeI), or reacting iPrN:BH 3 with 1 equiv of n-BuLi followed by trimethylsilyl chloride (TMSCl). BH2N(ZPr)2 prepared with MeI was found to reduce benzonitriles to the corresponding benzylamines at ambient temperatures, whereas diisopropylaminoborane prepared with TMSCl does not reduce nitriles unless a catalytic amount of a lithium ion source, such as LiBH4 or lithium tetraphenylborate (LiBPh4), is added to the reaction. The reductions of benzonitriles with one or more electron-withdrawing groups on the aromatic ring generally occur much faster with higher yields. For example, 2,4-dichlorobenzonitrile was successfully reduced to 2,4-dichlorobenzylamine in 99% yield after 5 h at 25 °C. On the other hand, benzonitriles containing electron-donating groups on the aromatic ring require refluxing in tetrahydrofuran (THF) for complete reduction. For instance, 4- methoxybenzonitrile was successfully reduced to 4-methoxybenzylamine in 80% yield. Aliphatic nitriles can also be reduced by the BH2N(iPr) 2/cat. LiBH4 reducing system. Benzyl cyanide was reduced to phenethylamine in 83% yield. BH2NOPr)2 can also reduce nitriles in the presence of unconjugated alkenes and alkynes such as the reduction of 2-hexynenitrile to hex-5-yn-l-amine in 80% yield. Unfortunately, selective reduction of a nitrile in the presence of an aldehyde is not possible as aldehydes are reduced along with the nitrile. However, selective reduction of the nitrile group at 25 °C in the presence of an ester is possible as long as the nitrile group is activated by an electron-withdrawing substituent. It should be pointed out that lithium aminoborohydrides (LABs) do not reduce nitriles under ambient conditions and behave as bases with aliphatic nitriles as well as nitriles containing acidic a-protons. Consequently, both LABs and BH2NOPr)2 are complementary to each other and offer methods for the selective reductions of multifunctional compounds.
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.
Process for preparation of 9-(dihalobenzyl) adenines
-
, (2008/06/13)
9-(Dihalobenzyl)adenines are prepared uncontaminated with other positional isomers in a series of mild transformations starting from 4,5,6-triaminopyrimidine and proceeding via 7-(N-formyl-N-dihalobenzyl)amino[1,2,5]thiadiazolo[3,4-d]pyrimidine. The resulting compounds have anticoccidial activity and are useful in controlling cecal and/or intestinal coccidiosis when administered in minor quantities to animals, in particular to poultry usually in admixture with animal sustenance.
