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2007年04月03日

【期刊论文】Efficient Stille Cross-Coupling Reaction Catalyzed by the Pd(OAc)2/Dabco Catalytic System

李金恒, Jin-Heng Li, Yun Liang, De-Ping Wang, Wen-Jie Liu, Ye-Xiang Xie, and Du-Lin Yin

J. Org. Chem. 2005, 70, 2832-2834,-0001,():

-1年11月30日

摘要

An efficient Pd(OAc)2/Dabco-catalyzed Stille cross-coupling reaction procedure has been developed. In the presence of Pd(OAc)2 and Dabco (triethylenediamine), various aryl halides including aryl iodides, aryl bromides, and activated aryl chlorides were coupled efficiently with organotin compounds to afford the corresponding biaryls, alkene, and alkynes in good to excellent yields. Furthermore, high TONs [turnover numbers, up to 980 000 TONs for the coupling reaction of 1-bromo-4-nitrobenzene and furan-2-yltributyltin] for the Stille cross-coupling reaction were observed.

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2007年04月03日

【期刊论文】General and Selective Synthesis of (Z)-3-Haloacrylates via Palladium-Catalyzed Carbonylation of Terminal Alkynes

李金恒, Jin-Heng Li, Shi Tang, and Ye-Xiang Xie

J. Org. Chem. 2005, 70, 477-479,-0001,():

-1年11月30日

摘要

A general and selective palladium-catalyzed carbonylation of terminal alkynes method for the synthesis of (Z)-3-haloacrylates is presented. In the presence of a catalytic amount of PdX2 and 5 equiv of CuX2 (X=Cl and Br), terminal alkynes were carbonylated to afford the corresponding (Z)-3-haloacrylates exclusively in moderate to good yields. The results showed that the effect of solvent had a fundamental influence on the chemoselectivity and stereoselectivity of the palladium-catalyzed carbonylation reaction.

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2007年04月03日

【期刊论文】Recyclable and Reusable Pd(OAc)2/DABCO/PEG-400 System for Suzuki-Miyaura Cross-Coupling Reaction

李金恒, Jin-Heng Li, Wen-Jie Liu, and Ye-Xiang Xie

J. Org. Chem. 2005, 70, 5409-5412,-0001,():

-1年11月30日

摘要

A stable and efficient Pd(OAc)2/DABCO (triethylenediamine) catalytic system for Suzuki-Miyaura cross-coupling reaction has been developed. In the presence of Pd(OAc)2 and DABCO, coupling of aryl halides with arylboronic acids was carried out smoothly to afford good to excellent yields and high turnover numbers (TONs) (the maximal TONs were up to 960 000 for the reaction of 1-iodo-4-nitrobenzene with phenylboronic acid) using PEG-400 as the solvent. Moreover, the Pd(OAc)2/DABCO/PEG-400 system could be recycled and reused five times without any loss of catalytic activity for aryl iodides and bromides.

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2007年04月03日

【期刊论文】Modified Palladium-Catalyzed Sonogashira Cross-Coupling Reactions under Copper-, Amine-, and Solvent-Free Conditions

李金恒, Yun Liang, Ye-Xiang Xie, and Jin-Heng Li

J. Org. Chem. 2006, 71, 379-381,-0001,():

-1年11月30日

摘要

PdCl2(PPh3)2 combined with TBAF under solvent-free conditions provided general and fast Sonogashira cross-coupling reactions of aryl halides with terminal alkynes. In particular, this protocol could be applied to the reactions of deactivated aryl chlorides. In the presence of 3 mol % of PdCl2(PPh3)2 and 3 equiv of TBAF, a number of ArX species (X=I, Br, Cl) were coupled with alkynes to afford the corresponding products in moderate to excellent yields under copper-, amine-, and solvent-free conditions.

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2007年04月03日

【期刊论文】Reusable Copper-Catalyzed Cross-Coupling Reactions of Aryl Halides with Organotins in Inexpensive Ionic Liquids

李金恒, Jin-Heng Li, Bo-Xiao Tang, Li-Ming Tao, Ye-Xiang Xie, Yun Liang, and Man-Bo Zhang

J. Org. Chem. 2006, 71, 7488-7490,-0001,():

-1年11月30日

摘要

A combination of Cu2O nanoparticles with P(o-tol)3 shows highly catalytic activity for the Stille cross-coupling reaction. A series of copper catalysts and ligands were evaluated, and Cu2O nanoparticles combined with P(o-tol)3 provided the best results. In the presence of Cu2O nanoparticles and P(o-tol)3, a variety of aryl halides including aryl chlorides underwent the Stille reaction with organotins smoothly in moderate to excellent yields using inexpensive TBAB (n-Bu4NBr) as the medium. It is noteworthy that the Cu2O/P(o-tol)3/TBAB system can be recovered and reused at least three times without any loss of catalytic activity among the reactions of aryl iodides and activated aryl bromides.

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    湖南大学,湖南

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