Showing papers by "Guochen Jia published in 2008"
TL;DR: The ruthenium-catalyzed azide-alkyne cycloaddition (RuAAC) appears to proceed via oxidative coupling of the azide and alkyne reactants to give a six-membered rUThenacycle intermediate, in which the first new carbon-nitrogen bond is formed between the more electronegative carbon of the alkynes and the terminal, electrophilic nitrogen of the Azide.
Abstract: The catalytic activity of a series of ruthenium(II) complexes in azide−alkyne cycloadditions has been evaluated. The [Cp*RuCl] complexes, such as Cp*RuCl(PPh3)2, Cp*RuCl(COD), and Cp*RuCl(NBD), were among the most effective catalysts. In the presence of catalytic Cp*RuCl(PPh3)2 or Cp*RuCl(COD), primary and secondary azides react with a broad range of terminal alkynes containing a range of functionalities selectively producing 1,5-disubstituted 1,2,3-triazoles; tertiary azides were significantly less reactive. Both complexes also promote the cycloaddition reactions of organic azides with internal alkynes, providing access to fully-substituted 1,2,3-triazoles. The ruthenium-catalyzed azide−alkyne cycloaddition (RuAAC) appears to proceed via oxidative coupling of the azide and alkyne reactants to give a six-membered ruthenacycle intermediate, in which the first new carbon−nitrogen bond is formed between the more electronegative carbon of the alkyne and the terminal, electrophilic nitrogen of the azide. This ...
721 citations
TL;DR: In this article, an A2 + B3 approach was used to synthesize hyperbranched poly(1,2,3-triazole)s with regioregularity, processability, and functionality.
Abstract: Synthesis of hyperbranched poly(1,2,3-triazole)s (hb-PTAs) has been a challenge: the AB2 monomers were inclined to self-oligomerize, and their Cu(I)-catalyzed click polymerizations failed to yield soluble polymers. We tackled the challenge in this work and succeeded in generating hb-PTAs with regioregularity, processability, and functionality. We took an A2 + B3 approach and used diazides 2 and triyne 3 as monomers, which are free of self-oligomerization concerns. Thermal polymerizations of 2 and 3 produced regiorandom polymers (hb-r-P1) with high molecular weights in high yields. Metal-mediated regioselective polymerizations afforded soluble 1,4- and 1,5-linked polymers (hb-1,4-P1 and hb-1,5-P1), presenting the first examples of regioregular hb-PTAs with macroscopic processability. The reactions were affected by substrate and catalyst: electron-rich alkyne generally slowed down the cycloaddition reaction, while ruthenium catalysts (Cp*Ru(PPh3)2Cl and [Cp*RuCl2]n) exhibited higher substrate tolerance than...
147 citations
TL;DR: In this paper, a computational study with the Becke3LYP DFT functional theory was carried out on Ni(0)-mediated coupling reactions of both terminal and internal alkynes with CO2.
41 citations
TL;DR: In this article, a mixture of cis and trans isomers of the π-allyl palladium complexes PdI(η3-MeCHC(Ph)CHR)(PPh3) in which the R group is anti and the Me group is syn to the Ph group was obtained.
36 citations
TL;DR: In this article, the mechanism of N2O O-insertion into the Ru−H bonds of ruthenium hydride complexes (DMpe)2Ru(H)(X) (X = OH, H).
30 citations
TL;DR: In this article, an optically active pyrazolidine derivatives from Pd(0)/( R, R )-Bn-BOX-catalyzed enantioselective cyclization of 3,4-allenylic hydrazines in the presence of organic halides has been developed, the ee value is 75-84%.
28 citations
TL;DR: In this paper, the reactions of Cp*RuCl(COD) with alkynes in different solvents were investigated, and the results showed that the reaction produces tricyclo[4.2.2] and free COD.
21 citations
TL;DR: 2-Vinylic cyclic 1,3-alkadienes can be obtained with moderate to good yields via the Cp*RuCl(PPh3)2-catalyzed coupling reaction of alkynes with cyclic allenes.
16 citations
TL;DR: In this article, the relative stability of the trans and cis isomers in the square planar palladium(II) complexes Pd(I)(PPh3)(η3-XCHC(Ph)CHR) was investigated with the aid of the B3LYP density functional theory calculations.
Abstract: The relative stability of the trans and cis isomers in the square planar palladium(II) complexes Pd(I)(PPh3)(η3-XCHC(Ph)CHR) (X = H, Me, CMe3, CO2Me, P(O)(OMe)2, and SO2H; R = H, Me) was investigated with the aid of the B3LYP density functional theory calculations. We examined how the substituents X, with different electronic properties, of the η3-allyl ligands affect the relative stability of the trans and cis isomers. Through the investigation, we were able to explain the trans/cis relative stability derived from the experimentally measured trans/cis isomer ratios in the palladium(II) complexes.
1 citations
TL;DR: In this article, a 2.2-Vinylic cyclic 1,3-alkadienes can be obtained with moderate to good yields via the Cp*RuCl(PPh3)2-catalyzed coupling reaction of alkynes with cyclic allenes.
Abstract: 2-Vinylic cyclic 1,3-alkadienes can be obtained with moderate to good yields via the Cp*RuCl(PPh3)2-catalyzed coupling reaction of alkynes with cyclic allenes.