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Current Organic Synthesis, Volume 1, No. 4, 2004

 

Contents

 

Transition Metal Complexes in Organic Synthesis, Part 70#. Synthesis of Biologically Active Carbazole Alkaloids Using Organometallic Chemistry Pp.309-331

Hans-Joachim Knolker

[Abstract]

 

Niobium Pentachloride in Organic Synthesis: Applications and Perspectives Pp.333-353

Carlos Kleber Z. Andrade

[Abstract]

 

Transition Metal-Promoted Syntheses of Vinylphosphonates Pp.355-375

Michel Maffei

[Abstract]

 

Fragmentation-Related Phosphinylation and Phosphonylation of Nucleophiles Utilising the Bridging P-Unit of 2-Phosphabicyclo[2.2.2]oct-5-ene Derivatives Pp.377-389

Gyorgy Keglevich, Helga Szelke and Janos Kovacs

[Abstract]

 

4-Alkoxy-1,1,1-Trichloro-3-Alken-2-ones: Preparation and Applications in Heterocyclic Synthesis Pp.391-403

Marcos A. P. Martins, Wilson Cunico, Claudio M. P. Pereira, Adilson P. Sinhorin, Alex F. C.Flores, Helio G. Bonacorso and Nilo Zanatta

[Abstract]  

 

Some New Trends and Recent Progress Towards Environmentally Benign Synthesis Pp.405-429

Sanzhong Luo, Yiyuan Peng, Baolian Zhang, Peng George Wang and Jin-Pei Cheng

[Abstract]  

  

Abstracts

 

[Back to top] Transition Metal Complexes in Organic Synthesis, Part 70#. Synthesis of Biologically Active Carbazole Alkaloids Using Organometallic Chemistry

Hans-Joachim Knolker

 

The isolation and biological activity of carbazole alkaloids is summarized. Recent developments of novel methodologies for the synthesis of carbazole alkaloids are described. The focus is on syntheses using the oxidative coupling of arylamines with either arenes, cyclohexadienes, or cyclohexene mediated or catalyzed by palladium, iron, or molybdenum. The implementation of these annulations in total syntheses provides highly convergent routes to biologically active carbazole alkaloids. Advantages, scope, and limitations of the different synthetic methods are discussed.

 

[Back to top] Niobium Pentachloride in Organic Synthesis: Applications and Perspectives

Carlos Kleber Z. Andrade

 

Niobium pentachloride has proved to be a powerful activating agent for various organic reactions. This oxophylic reagent possesses a good Lewis acidity and has received increasing attention in recent years. Different outcomes from more common Lewis acids have been achieved in some reactions. In this review, the applications of this versatile reagent in organic synthesis will be disclosed.

 

[Back to top] Transition Metal-Promoted Syntheses of Vinylphosphonates

Michel Maffei

 

This review summarizes the different synthetic methods for the preparation of vinylphosphonates based exclusively on the use of transition metal complexes as promoters, i.e. employed in stoichiometric or catalytic amounts.

 

[Back to top] Fragmentation-Related Phosphinylation and Phosphonylation of Nucleophiles Utilising the Bridging P-Unit of 2-Phosphabicyclo[2.2.2]oct-5-ene Derivatives

Gyorgy Keglevich, Helga Szelke and Janos Kovacs

 

The synthesis of phosphonic and phosphinic derivatives comprises the use of the corresponding phosphorus chlorides. A novel approach applies low-coordinated P-species, methylenephosphine oxides (YP(O)CH2, Y =Ar, alkyl, alkoxy), which can be generated by the fragmentation of bridged P-heterocycles, 2- phosphabicyclo[2.2.2]oct-5-enes available by Diels-Alder cycloadditions. The fine tuning between the structure and reactivity of different type of precursors is discussed. Thermolysis or photolysis of the suitable phosphabicyclooctenes in the presence of hydroxy compounds or amines affords a rich variety of phosphinic or phosphonic derivatives. The potential of the photolysis is that it requires mild conditions (26 °C) and that it is highly efficient.

 

[Back to top] 4-Alkoxy-1,1,1-Trichloro-3-Alken-2-ones: Preparation and Applications in Heterocyclic Synthesis

Marcos A. P. Martins, Wilson Cunico, Claudio M. P. Pereira, Adilson P. Sinhorin, Alex F. C.Flores, Helio G. Bonacorso and Nilo Zanatta

 

The preparation of 4-alkoxy-1,1,1-trichloro-3-alken-2-ones (enones), important synthetic tools for the heterocyclic synthesis, from cheap and easily accessible starting materials, is reported. The applications of the enones in the synthesis of isoxazoles, pyrazoles, pyrimidines and other heterocycles are also reported. This review was grouped into two main sections: (i) synthesis of 4-alkoxy-1,1,1-trichloro-3-alken-2-ones and derivatives and (ii) applications of 4-alkoxy-1,1,1-trichloro-3-alken-2-ones in heterocyclic synthesis.

 

[Back to top] Some New Trends and Recent Progress Towards Environmentally Benign Synthesis

Sanzhong Luo, Yiyuan Peng, Baolian Zhang, Peng George Wang and Jin-Pei Cheng

 

With the advent of green chemistry, the importance of environmentally benign synthesis has been increasingly recognized. This review summarizes recent progresses in this field, covering mainly the organocatalysis, lanthanide triflate catalysis, and our recent related works. Emphasis will be paid on synthetic applications and their significance to green technology by using environmentally friendly reagents and solvents such as water and ionic liquids. In addition, some new trends in the related areas such as chemoenzymatic catalysis and organic synthesis in ionic liquid will be discussed.