107941-24-2Relevant academic research and scientific papers
Enantioselective Intermolecular Radical C-H Amination
Jin, Li-Mei,Xu, Pan,Xie, Jingjing,Zhang, X. Peter
, p. 20828 - 20836 (2020)
Radical reactions hold a number of inherent advantages in organic synthesis that may potentially impact the planning and practice for construction of organic molecules. However, the control of enantioselectivity in radical processes remains one of the longstanding challenges. While significant advances have recently been achieved in intramolecular radical reactions, the governing of asymmetric induction in intermolecular radical reactions still poses challenging issues. We herein report a catalytic approach that is highly effective for controlling enantioselectivity as well as reactivity of the intermolecular radical C-H amination of carboxylic acid esters with organic azides via Co(II)-based metalloradical catalysis (MRC). The key to the success lies in the catalyst development to maximize noncovalent attractive interactions through fine-tuning of the remote substituents of the D2-symmetric chiral amidoporphyrin ligand. This noncovalent interaction strategy presents a solution that may be generally applicable in controlling reactivity and enantioselectivity in intermolecular radical reactions. The Co(II)-catalyzed intermolecular C-H amination, which operates under mild conditions with the C-H substrate as the limiting reagent, exhibits a broad substrate scope with high chemoselectivity, providing effective access to valuable chiral amino acid derivatives with high enantioselectivities. Systematic mechanistic studies shed light into the working details of the underlying stepwise radical pathway for the Co(II)-based C-H amination.
Operationally simple copper-promoted coupling of terminal alkynes with benzyl halides
Davies, Katherine A.,Abel, Ryan C.,Wulff, Jeremy E.
supporting information; experimental part, p. 3997 - 4000 (2009/10/01)
(Chemical Equation Presented) Benzyl chlorides and bromides are shown to undergo copper-promoted coupling with a variety of terminal alkynes including, for the first time, electron-poor acetylenes such as methyl propiolate. The reaction permits easy acces
Synthetic Approach to Aklavinone Using 2-Oxo-2H-pyran-5-carboxylate (Coumalate) Intermediates
Jung, Michael E.,Hagenah, Jeffrey A.
, p. 1889 - 1902 (2007/10/02)
A novel approach for the preparation of aklavinone 5 is described in which the key step is the cycloaddition of a substituted coumalate with a ketene acetal to produce a masked A ring with the C and D rings attached.The 4-(arylmethyl)coumalate 53 was prepared from naphthalene-1,5-diol (6) by a seven step route involving as the key step the cyclocondensation of the methyl (arylmethyl)propiolate 52 with methyl 3-oxopentanoate 10.Cycloaddition of 53 with dimethyl ketene acetal 12 produced the potential A-ring precursor 67, which could not be cleanly reduced, thereby ending this scheme.The preparation of functionalized 4,6-dialkylpyrone-5-carboxylates and their use in the synthesis of bicyclic lactones and substituted benzoates via cycloaddition reactions are also described.
