41437-90-5Relevant academic research and scientific papers
Pd-Catalyzed Carbonylation of Vinyl Triflates to Afford α,β-Unsaturated Aldehydes, Esters, and Amides under Mild Conditions
Zhang, Shaoke,Neumann, Helfried,Beller, Matthias
supporting information, p. 3528 - 3532 (2019/05/24)
An efficient and general protocol for the synthesis of α,β-unsaturated aldehydes, esters, and amides via carbonylation of vinyl triflates including derivatives of camphor, ketoisophorone, verbenone, and pulegone was developed. Crucial for these transformations is the use of a specific palladium catalyst containing a pyridyl-substituted dtbpx-type ligand. This procedure also allows for an easy access of dicarbonylated products from the corresponding ketones.
Palladium catalysts for the formylation of vinyl triflates to form α,β-unsaturated aldehydes
Neumann, Helfried,Sergeev, Alexey,Beller, Matthias
scheme or table, p. 4887 - 4891 (2009/02/08)
(Chemical Equation Presented) What a gas! Synthesis gas is the formylating agent in the efficient one-step title transformation promoted by a palladium catalyst with the bidentate ligand 1,2-bis(di-1-adamantylphosphinomethyl)benzene (see scheme). This method enables the conversion of six-to eight-membered-ring triflates into α,β-unsaturated aldehydes and the introduction of a formyl group into derivatives of elaborate natural compounds. Tf = trifluoromethanesulfonyl.
Bacteriorhodopsin. The influence of the cyclohexene-ring methyls
Courtin, J. M. L.,Verhagen, L.,Biesheuvel, P. L.,Lugtenburg, J.,Bend, R. L. van der,Dam, K. van
, p. 112 - 119 (2007/10/02)
Four ring-demethylated retinals, viz. 1,1',5-tridemethylretinal, 1,1'-didemethylretinal, 1,5-didemethylretinal and 1-demethylretinal, have been synthesized via new and simple schemes.The properties of these modified retinals, their protonated Schiff bases and the corresponding bacteriorhodopsins have been studied and compared with the native system.These bacteriorhodopsin analogues have also been tested for their proton-pump efficiencies.A large decrease in proton-pump activity was found for the analogues lacking the 5-methyl group.On the whole, the opsin shifts of the modified bacteriorhodopsins were much lower than those of the native system.UV-Vis and 1H NMR data support a planar 6-s-trans conformation for the demethylated retinals in solution rather than a twisted 6-s-cis conformation (torsion angle 40-60 deg) as found in retinal.This explains the lower opsin shift and the better fit of these demethylated retinals in bacteriorhodopsin's binding site, which, in its native form, contains a 6-s-trans chromophore.
Facile Synthesis of Allylic Nitro Compounds by N,N-dimethylethylenediamine-Catalyzed Condensation of Aliphatic and Alicyclic Ketones with Primary Nitroalkanes
Tamura, Rui,Sato, Masahiro,Oda, Daihei
, p. 4368 - 4375 (2007/10/02)
Aliphatic as well as alicyclic ketones condense with primary nitroalkanes in the presence of N,N-dimethylethylenediamine (1) to give allylic nitro compounds selectively in good to excellent yields without forming α-nitro olefins.Condensation of 2-alkanones and 2-methylcyclopentanone with nitromethane produces the products of thermodynamic control, while the product of kinetic control is obtained from 2-methylcyclohexanone.Propiophenone, an aromatic ketone, reacted with nitromethane in a way analogous to aliphatic ketones to give the corresponding allylic nitro product.A reaction mechanism to account for the exclusive formation of allylic nitro compounds is proposed.Some allylic nitro compounds thus obtained are converted into α,β-unsaturated aldehydes and ketones by treatment with sodium methoxide and then TiCl3 in buffered solution.
