**Alkene Synthesis**

sis of various routes of oxidation of the simplest conjugated diolefin, 1,3-butadiene (BD), is the main objective of the fourth chapter, followed by the *polyolefins in the fifth chapter. In this last chapter, two different types of polyolefins are considered, polyolefin fibers and* polyolefin sul‐ fone, along with their applications in photodegradable plastics and *reinforcement of concrete,*

**Dr. Reza Davarnejad**

Arak University, Arak, Iran

**Baharak Sajjadi**

Research Assistant Professor,

Department of Chemical Engineering, University of Mississippi, U.S.A

Associate Professor of Chemical Engineering Department,

*respectively.* We hope that *Alkenes* will benefit the readers.

VIII Preface

**Chapter 1**

**Provisional chapter**

**Tandem-, Domino- and One-Pot Reactions Involving**

**Wittig- and Horner-Wadsworth-Emmons Olefination**

**Tandem-, Domino- and One-Pot Reactions Involving** 

DOI: 10.5772/intechopen.70364

**Wittig- and Horner-Wadsworth-Emmons Olefination**

The Wittig olefination utilizing phosphoranes and the related Horner-Wadsworth-Emmons (HWE) reaction using phosphonates transform aldehydes and ketones into substituted alkenes. Because of the versatility of the reactions and the compatibility of many functional groups towards the transformations, both Wittig olefination and HWE reactions are a mainstay in the arsenal of organic synthesis. Here, an overview is given on Wittig- and Horner-Wadsworth-Emmons (HWE) reactions run in combination with other transformations in one-pot procedures. The focus lies on one-pot oxidation Wittig/HWE protocols, Wittig/HWE olefinations run in concert with metal catalyzed cross-coupling reactions, Domino Wittig/HWE—cycloaddition and Wittig-Michael transformations.

**Keywords:** Wittig olefination, one-pot reactions, Domino reactions, tandem reactions,

The Wittig olefination utilizing phosphoranes and the related Horner-Wadsworth-Emmons (HWE) reaction using phosphonates transform aldehydes and ketones into substituted alkenes. Because of the versatility of the reactions and the compatibility of many functional groups in the transformations, both Wittig olefination and HWE reactions are a mainstay in the arsenal of organic synthesis. The mechanism of the Wittig olefination has been the subject of intense debate [1]. While initially it was supposed that all Wittig olefination reactions lead via 1,2-addition to betaine structures **4** as zwitterionic intermediates that would form oxaphosphetane **3** with a final release of alkene and phosphine oxide by ring opening (*syn*-cycloreversion process), it has been seen more recently that especially under salt-free, aprotic conditions, many ylides undergo

> © 2016 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution,

© 2018 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

and reproduction in any medium, provided the original work is properly cited.

Fatima Merza, Ahmed Taha and Thies Thiemann

Additional information is available at the end of the chapter

Horner-Wadsworth-Emmons olefination

Additional information is available at the end of the chapter

http://dx.doi.org/10.5772/intechopen.70364

Fatima Merza, Ahmed Taha and

Thies Thiemann

**Abstract**

**1. Introduction**

**Provisional chapter**
