Gold(<scp>i</scp>)-catalyzed addition of carboxylic acids to internal alkynes in aqueous medium
作者:Pedro J. González-Liste、Sergio E. García-Garrido、Victorio Cadierno
DOI:10.1039/c6ob02800d
日期:——
We report herein the efficient hydro-oxycarbonylation of symmetrical and unsymmetrical internal alkynes with carboxylic acids in water at 60 °C, employing the catalytic system [AuCl(PPh3)]/AgOAc (5 mol%). This simple and eco-friendly protocol allows for the synthesis of a wide variety of trisubstituted enol esters (37 examples) in high yields and with complete Z-stereoselectivity. The use of microwave
Pourcelot,G.; Cadiot,P., Bulletin de la Societe Chimique de France, 1966, p. 3016 - 3024
作者:Pourcelot,G.、Cadiot,P.
DOI:——
日期:——
Rijn, P. E. van; Everhardus, R. H.; Ven, J. van der, Recueil des Travaux Chimiques des Pays-Bas, 1981, vol. 100, # 10, p. 372 - 375
作者:Rijn, P. E. van、Everhardus, R. H.、Ven, J. van der、Brandsma, L.
DOI:——
日期:——
Twisted Cycloalkynes and Remote Activation of “Click” Reactivity
作者:Trevor Harris、Gabriel dos Passos Gomes、Suliman Ayad、Ronald J. Clark、Vladislav V. Lobodin、Megan Tuscan、Kenneth Hanson、Igor V. Alabugin
DOI:10.1016/j.chempr.2017.07.011
日期:2017.10
The "twisted and bent'' cyclodecyne structural motif, intertwined with dormant electronic effects, opens a conceptually powerful way to control "click'' reactivity. The endocyclic heteroatoms of cyclodecynes provide dual electronic activation via hyperconjugative (direct) and conjugative (remote) effects. These effects are weakened by the geometric constraints imposed by the twisted backbone, but structural reorganization in the transition state (TS) removes these constraints and unlocks the power of remote electronic effects for selective TS stabilization. Gram-scale synthesis and purification by recrystallization make this an efficient and practical approach to enantiopure cycloalkynes. Experimental kinetics confirm that these twisted cyclodecynes can be more reactive toward azides than activated cyclononynes and approach the reactivity of cyclooctynes. Furthermore, cycloalkynes with a twisted polyaromatic backbone can potentially add axial chirality to the "click'' chemistry toolbox.