Metal-Free Amidation of Ethers with N,N-Dibromosulfonamides
摘要:
A new metal-free amidation of ethers with N,N-dibromosulfonamides has been developed. A series of hemiaminal ethers or imines were prepared with moderate to good yields.
Imido Transfer from Bis(imido)ruthenium(VI) Porphyrins to Hydrocarbons: Effect of Imido Substituents, C−H Bond Dissociation Energies, and Ru<sup>VI/V</sup> Reduction Potentials
(BDE) of the hydrocarbons. A linear correlation was observed between log k' (k' is the k2 value divided by the number of reactive hydrogens) and BDE and between log k2 and E(1/2)(Ru(VI/V)); the linearity in the former case supports a H-atom abstraction mechanism. The amidation by [Ru(VI)(TMP)(NNs)2] reverses the thermodynamic reactivity order cumene > ethylbenzene/toluene, with k'(tertiary C-H)/k'(secondary
in formal insertions into CHbonds, activated by phenyl or vinyl groups, or by O-substituents. Scope and limitations of the reaction were investigated. Yields of up to 84% were achieved in the most favorable cases. Yields were enhanced by electron-releasing substituents and decreased by steric hindrance. Aziridination competed with allylic insertion with olefinic substrates. The insertion reaction proceeded
The [Rh-2(OAc)(4)]-catalyzed decomposition of NsN=IPh [N-(p-nitrobenzenesulfonyl)imino]phenyliodinane} in the presence of olefins affords aziridines in yields of up to 85%. The aziridination of cis-hex-2-ene and cis-beta- methylstyrene is stereospecific, but, cis-stilbene affords a 3:1 mixture of cis- and trans-aziridines in low yield. With chiral Rh(II) catalysts, optically active aziridines are formed having enantiomeric excesses of up to 73%. The NsN=IPh-[Rh-2(OAc)(4)] system is also efficient for the allylic amination of olefins and for insertion into CH bonds, activated by phenyl or oxygen substituents.