Reaksi Grignard: Perbedaan antara revisi

Pereaksi Grignard dibuat melalui reaksi antara alkil atau aril halida dengan [[logam]] [[magnesium]]. Reaksi dilakukan dengan penambahan halida organik ke dalam suspensi magnesium dalam pelarut [[eter]], yang menghasilkan [[Ligan (biokimia)|ligan]] yang diperlukan untuk menstabilkan [[Kimia organologam golongan 2|senyawa organomagnesium]]. Bukti empiris menunjukkan bahwa reaksi berlangsung pada permukaan logam. Reaksi berlangsung melalui [[Radikal bebas|transfer elektron tunggal]]:<ref>Garst, J.F.; Ungvary, F. "Mechanism of Grignard reagent formation". In <nowiki>''</nowiki>Grignard Reagents<nowiki>''</nowiki>; Richey, R.S., Ed.; John Wiley & Sons: New York, 2000; pp 185–275. <nowiki>ISBN 0-471-99908-3</nowiki>. </ref><ref>''Advanced Organic chemistry Part B: Reactions and Synthesis'' F.A. Carey, R.J. Sundberg 2nd Ed. 1983</ref><ref>{{Cite|doi = 10.1021/ja00521a034|title = Mechanism of formation of Grignard reagents. Kinetics of reaction of alkyl halides in diethyl ether with magnesium|year = 1980|last1 = Rogers|first1 = H.R.|last2 = Hill|first2 = C.L.|last3 = Fujiwara|first3 = Y.|last4 = Rogers|first4 = R.J.|last5 = Mitchell|first5 = H.L.|last6 = Whitesides|first6 = G.M.|journal = Journal of the American Chemical Society|volume = 102|issue = 1|page = 217}}</ref> Dalam reaksi pembentukan Grignard, radikal bebas dapat dikonversi menjadi karbanion melalui transfer elektron kedua.<ref>{{Cite journal|last1 = De Boer|first1 = H.J.R.|last2 = Akkerman|first2 = O.S.|last3 = Bickelhaupt|first3 = F.|year = 1988|title = Carbanions as intermediates in the synthesis of Grignard Reagents|journal = Angew. Chem. Int. Ed.|volume = 27|issue = 5|pages = 687–89|doi = 10.1002/anie.198806871}}</ref><ref>{{Cite journal|last1 = Van Klink|first1 = G.P.M.|last2 = de Boer|first2 = H.J.R.|last3 = Schat|first3 = G.|last4 = Akkerman|first4 = O.S.|last5 = Bickelhaupt|last6 = Spek|first5 = F.|first6 = A.|year = 2002|title = Carbanions as Intermediates in the Formation of Grignard Reagents|journal = Organometallics|volume = 21|issue = 10|pages = 2119–35|doi = 10.1021/om011083a}}</ref>

Untuk kegunaan ini, pereaksi Grignard komersial sangat berguna karena dapat menghindari masalah pada tahap inisiasi.<ref>Silverman, G.S.; Rakita, P.E. (eds.) (1996) ''Handbook of Grignard Reagents''. CRC Press. <nowiki>ISBN 0-8247-9545-8</nowiki> </ref>