1056246-49-1Relevant articles and documents
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Sehgal,R.K. et al.
, p. 3073 - 3078 (1975)
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Silica gel catalyzed α-bromination of ketones using N-bromosuccinimide: An easy and rapid method
Mohan Reddy, Bodireddy,Venkata Ramana Kumar, Velpula,Chinna Gangi Reddy, Nallagondu,Mahender Rao, Siripragada
, p. 179 - 182 (2014)
An easy and rapid method for the α-bromination of ketones using N-bromosuccinimide (NBS) catalyzed by silica gel in methanol under reflux conditions was developed. The expected products were formed in excellent isolated yields within a short period of time (5-20 min). Major advantages of the present procedure include use of inexpensive and readily available catalyst, exclusion of pre- and post-chemical treatment of catalyst and use of methanol as solvent instead of ethers and chlorinated solvents.
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Olah,G.A. et al.
, p. 3653 - 3656 (1979)
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A simple and selective procedure for α-bromination of alkanones using hexamethylenetetramine-bromine complex and basic alumina in solvent-free conditions
Paul, Satya,Gupta, Varinder,Gupta, Rajive
, p. 1917 - 1922 (2003)
α-Bromoalkanones 2 were synthesized by the reaction of alkanones 1 with hexamethylenetetramine-bromine complex and basic alumina in solvent-free conditions under microwave irradiation.
A new and versatile one-pot strategy to synthesize alpha-bromoketones from secondary alcohols using ammonium bromide and oxone
Rammurthy, Banothu,Swamy, Peraka,Naresh, Mameda,Srujana, Kodumuri,Durgaiah, Chevella,Krishna Sai, Gajula,Narender, Nama
, p. 3710 - 3714 (2017)
A new, efficient and green protocol for the one-pot synthesis of α-bromoketones from secondary alcohols using cheap, air stable and non-toxic reagents such as NH4Br and oxone has been developed. This reaction proceeds via two consecutive steps such as oxidation of secondary alcohols and oxidative bromination of in situ generated ketones.
Infrared and theoretical calculations in 2-halocycloheptanones conformational analysis
Rozada, Thiago C.,Gauze, Gisele F.,Favaro, Denize C.,Rittner, Roberto,Basso, Ernani A.
, p. 277 - 287 (2012)
2-Halocycloheptanones (Halo = F, Cl, Br and I) were synthesized and their conformational analysis was performed through infrared spectroscopy data. The corresponding conformers geometries and energies were obtained by theoretical calculations at B3LYP/aug-cc-pVDZ level of theory in the isolated state and in solution. It was observed, by both approaches, that the conformational preferences were very sensitive to the solvent polarity, since its increase led to an increase in the population of the more polar conformer. An analysis of these conformational equilibria showed they suffer also the influence of stereoelectronic effects, like hyperconjugation and steric effects. These results were interpreted using natural bond orbital (NBO) analysis, which indicated that the electronic delocalization to the orbital π* CO is directly involved in the stability increase of conformers I and II. The relative effect of the period of the halogen can also be noted, with changes in the conformational preferences and in the energies involved in the interactions of NBO.
Diastereoselective Additions of Allylmagnesium Reagents to α-Substituted Ketones When Stereochemical Models Cannot Be Used
Bartolo, Nicole D.,Demkiw, Krystyna M.,Valentín, Elizabeth M.,Hu, Chunhua T.,Arabi, Alya A.,Woerpel
, p. 7203 - 7217 (2021/05/29)
The stereoselectivities of reactions of allylmagnesium reagents with chiral ketones cannot be easily explained by stereochemical models. Competition experiments indicate that the complexation step is not reversible, so nucleophiles cannot access the widest range of possible encounter complexes and therefore cannot be analyzed easily using available models. Nevertheless, additions of allylmagnesium reagents to a ketone can still be stereoselective provided that the carbonyl group adopts a conformation that leads to one face being completely blocked from the approach of the allylmagnesium reagent.
Total Synthesis of Galanthamine and Lycoramine Featuring an Early-Stage C-C and a Late-Stage Dehydrogenation via C-H Activation
Zhang, Yuna,Shen, Shuna,Fang, Hua,Xu, Tao
supporting information, p. 1244 - 1248 (2020/01/31)
Herein, we report a novel strategy toward galanthamine and lycoramine. The concise synthesis was enabled by a Rh-catalyzed gram-scale C-C activation for the tetracyclic carbon framework and a regioselective Pd-catalyzed C-H activation for double-bond introduction. An aqueous-phase Beckmann rearrangement was performed for nitrogen atom insertion. Galanthamine and lycoramine were completed in 11 and 10 steps, respectively.
