Editing Reductive dechlorination (section)

==Chemical==
Dechlorination is a well-researched reaction in organic [[Organic synthesis|synthesis]], although it is not often used. Usually stoichiometric amounts of dechlorinating agent are required. In one  classic application, the [[Ullmann reaction]], chloroarenes are coupled to [[biphenyl]]s.  For example, the activated substrate [[2-Chloronitrobenzene|2-chloronitrobenzene]] is converted into 2,2'-dinitro[[biphenyl]] with a copper - bronze [[alloy]].<ref>{{cite journal|title=2,2'-Dinitrobiphenyl
|author=Reynold C. Fuson |author2=E. A. Cleveland
|journal=Org. Synth.|year=1940|volume=20|page=45
|doi=10.15227/orgsyn.020.0045}}</ref><ref>{{cite journal | last1 = Fanta | first1 = P.E. | year = 1974 | title = The Ullmann Synthesis of Biaryls | journal = Synthesis | volume = 1974 | pages = 9–21 | doi = 10.1055/s-1974-23219 | pmid = 21016995 }}</ref>
[[Image:UllmannReaction.svg|center|Ullmann reaction.]]

[[Zerovalent iron]] effects similar reactions. [[Organophosphorus compound|Organophosphorus(III) compounds]] effect gentle dechlorinations. The products are alkenes and phosphorus(V).<ref>{{cite journal |doi=10.15227/orgsyn.046.0093|author=V. Mark|title=Perchlorofulvalene|journal=Organic Syntheses|year=1966|volume=46|page=93}}</ref>  
*Alkaline earth metals and zinc are used for more difficult dechlorinations.  The side product is zinc chloride.<ref>{{cite journal |first1=Rick L. |last1=Danheiser|first2=Selvaraj|last2=Savariar|first3=Don D.|last3= Chad|doi=10.15227/orgsyn.068.0032|title=3-Butylcyclobutenone|journal=Organic Syntheses|year=1990|volume=68|page=32}}</ref>