Dongmei Xu

Dual Roles of Sulfonyl Hydrazides: A Three-Component Reaction To Construct Fully Substituted Pyrazoles Using TBAI/TBHP

A mild and rapid approach has been developed for the construction of fully substituted pyrazoles using TBAI as a catalyst and TBHP as an oxidant, in which tosylhydrazide functions as the ring component and sulfonyl precursor. This protocol features a wide substrate scope with a broad range of functional group tolerance, utilizes easily available starting materials, can be scaled-up, and is operationally simple.

Interception of Cobalt-Based Carbene Radicals with α-Aminoalkyl Radicals: A Tandem Reaction for the Construction of β-Ester-γ-amino Ketones†

The interception of cobalt-based carbene radicals with α-aminoalkyl radicals was combined with the Kornblum-DeLaMare reaction and provides β-ester-γ-amino ketones, which are otherwise difficult to obtain in high chemoselectivity. Mechanistically, this transformation is an interplay of cobalt-based carbene radicals, organoradicals, and ionic intermediates and involves the construction of two C-C bonds and one C=O bond in a one-pot process. The reaction also features a wide substrate scope and is highly efficient and insensitive to moisture and air.

A new series of dendrimers containing two ferrocenyl units and a Fréchet dendron around a triazine nucleus

The preparation and characterization of a new series of dendrimers containing two identical aminoferrocenyl units and a Fréchet dendron around a triazine nucleus is described. A sizable degree of electronic communication between the two redox active ferrocenyl residues was detected in dichloromethane solution containing tetrabutylammonium tetra(pentafluorophenyl)borate as the supporting electrolyte. Binding of glutarimide via hydrogen bonding interactions to all the dendrimers was easily detected by using (1)H NMR spectroscopic and voltammetric techniques.

Synthesis and Characterization of Dendrimers from Ethylene Diamine and Trimethylolpropane Triacrylate

Dendrimers were prepared from ethylene diamine (EDA) and trimethylolpropane triacrylate (TMPTA) by Michael addition reaction under mild conditions. EDA with four functional groups and TMPTA with three functional groups reacted directly without protection‐deprotection steps. The terminated functional groups of the whole dendrimer generation grew at the rate of 8×6n−1, and some objective products could be isolated and purified by washing with selective solvents. The dendrimer structure was characterized by IR, 1H NMR, 13C NMR, elemental analysis and ESI‐MS. The influence of reaction conditions on yields and purities of dendrimers was discussed.

Bisaminoferrocenyl triazine derivatives: effects of the third substituent on the extent of interaction between the metal centers

We prepared a new series of bisaminoferrocenyl triazine derivatives and investigated their anodic voltammetric behavior. The electronic nature of the third substituent on the triazine nucleus, that is, its electronic donor/acceptor character determines the level of interactions between the two ferrocenyl centers as measured by the separation between their two oxidation half-wave potentials.