64505-07-3Relevant academic research and scientific papers
Iron-catalysed 1,2-acyl migration of tertiary α-azido ketones and 2-azido-1,3-dicarbonyl compounds
Yang, Tonghao,Lin, Yajun,Yang, Chaoqun,Yu, Wei
supporting information, p. 6097 - 6102 (2019/11/20)
Iron-catalysed 1,2-acyl migration of tertiary α-azido ketones and 2-azido-1,3-dicarbonyl compounds provides a simple and atom-economical approach toward enamides and isoquinolones. This paper reports two catalyst systems for these transformations which employ iron(ii) complexes [Fe(dpbz)]Br2 (dpbz = 1,2-bis(diphenylphosphino)benzene) and FeBr2/Et3N, respectively. [Fe(dpbz)]Br2 was found to be highly effective at converting 2-azido-2,3-dihydro-1H-inden-1-ones to isoquinolones. The reagent combination of FeBr2/Et3N, on the other hand, exhibited a broader catalytic scope, owing to the beneficial effect of Et3N. This latter catalyst system enables 2-azido-2-methyl-1,3-dicarbonyl compounds to be converted to the corresponding enamides under mild conditions in good yields.
Rhodium-catalyzed Asymmetric Hydrogenation of α-Dehydroamino Ketones: A General Approach to Chiral α-amino Ketones
Gao, Wenchao,Wang, Qingli,Xie, Yun,Lv, Hui,Zhang, Xumu
supporting information, p. 231 - 233 (2016/02/27)
Rhodium/DuanPhos-catalyzed asymmetric hydrogenation of aliphatic α-dehydroamino ketones has been achieved and afforded chiral α-amino ketones in high yields and excellent enantioselectives (up to 99 % ee), which could be reduced further to chiral β-amino alcohols by LiAlH(tBuO)3 with good yields. This protocol provides a readily accessible route for the synthesis of chiral α-amino ketones and chiral β-amino alcohols. Taking a different route: Rh/DuanPhos is shown to be an effective catalyst for the asymmetric hydrogenation of α-dehydroamino ketones, affording aliphatic α-amino ketones in high yields and excellent enantioselectivities. This method provides an efficient and general route to the synthesis of chiral aliphatic α-amino ketones and α-amino alcohols.
Asymmetric transfer hydrogenation of α,β-unsaturated, α-tosyloxy and α-substituted ketones
Peach, Philip,Cross, David J.,Kenny, Jennifer A.,Mann, Inderjit,Houson, Ian,Campbell, Lynne,Walsgrove, Tim,Wills, Martin
, p. 1864 - 1876 (2007/10/03)
Asymmetric transfer hydrogenation of cyclic and acyclic α,β-unsaturated ketones catalysed by η6-p-cymene/ ruthenium(II) and η5-pentamethylcyclopentadienyl/rhodium(III) complexes have been investigated. Cyclic α,β-unsaturated ketones appeared to be more suitable substrates for the synthesis of enantiomerically pure allylic alcohols than do acyclic α,β-unsaturated ketones. A proposed mechanism for the formation of 4-phenyl-[1,3]-dioxolan-2-one from α-tosyloxy- and halo-substituted acetophenones is discussed. The results of further investigations into the reduction of a range of α- tosyloxyacetophenones and the dynamic kinetic resolution of α-substituted ketones is presented.
Reaction of 3-(Acetoxyamino)quinazolin-4(3H)-ones with Enolic β-Diketones: the N-N Bond as a Chiral Axis in N-(3,4-dihydro-4-oxoquinazolin-3-yl)-N-acyl-α-aminoketones; Reductive and Base-catalysed Cleavage of the N-N Bond in N-Acetyl-N-(3,4-dihydro-4-oxoquinazolin-3-yl)-α-amino Aci...
Atkinson, Robert S.,Edwards, Paul J.,Thomson, Gordon A.
, p. 3209 - 3216 (2007/10/02)
Following the method of Foucaud and coworkers, reaction of pentane-2,4-dione with 3-(acetoxyamino)quinazolin-4-one 8 gave the keto amide 9 (15percent). 3-Methylpentane-2,4-dione reacts with compound 8 to give a relatively stable enol 11 (66percent) which can be isolated in a crystalline form.Rotation around the N-N bonds in both compounds 9 and 11 is believed to be slow on the real time-scale and hence the N-N bonds can be considered as a chiral axes.As a result, protonation of the enol double bond in compound 11 and the creation of an additional chiral centre, gives rise to the separable keto amides 14 and 15; this protonation can be accomplished completely diastereoselectively.Lead tetraacetate acetoxylation of compound 11 to give compound 11 to give compound 19 is also completely diastereoselective.Brief heating of the enol effects the elimination of the quinazolinone and the formation of the N-acetylimine 16 via an 8-membered transition state.Base-catalysed elimination of the quinazolinone ring from compound 22 is surprisingly easy: reductive cleavage of this N-N bond in compound 22 is facile by comparison with the 3-(alkylamino)quinazolin-4-ones.
Decomposition of 2-Azido Ketones to 2-(Acetylamino)-2-alken-1-ones by Perrhenate Catalysis
Effenberger, Franz,Beisswenger, Thomas,Az, Rainer
, p. 4869 - 4876 (2007/10/02)
The thermally induced elimination of nitrogen from cyclic and acyclic 2-azido ketones 2 is accelerated by catalytic amounts of perrhenate.In acetic anhydride - if necessary in the presence of small amounts of a mineral acid - 2-(acetylamino)-2-alken-1-ones 3 are formed in good yields.The decomposition rates of the catalysed and the uncatalysed thermolysis are compared.
