title: Air-stable solid aryl and heteroaryl organozinc pivalates: syntheses and applications in organic synthesis.
abstract: A wide range of air-stable, solid, polyfunctional aryl and heteroarylzinc pivalates were efficiently prepared by either magnesium insertion or Hal/Mg exchange followed by transmetalation with Zn(OPiv)2 (OPiv = pivalate). By reducing the amount of LiCl the air stability could be significantly enhanced compared with previously prepared reagents. An alternative route is directed magnesiation using TMPMgCl⋅LiCl (TMP = 2,2,6,6-tetramethylpiperidyl) followed by transmetalation with Zn(OPiv)2 or, for very sensitive substrates, direct zincation by using TMPZnOPiv. These zinc reagents not only show excellent stability towards air, but they also undergo a broad range of C-C bond-formation reactions, such as allylation and carbocupration reactions, as well as addition to aldehydes and 1,4-addition reactions. Acylation reactions can be performed by using an excess of TMSCl to overcome side reactions of the omnipresent pivalate anion.
authors.affiliation: Department Chemie, Ludwig-Maximilians-Universität München, Butenandtstrasse 5-13, Haus F, 81377 München (Germany), Fax: (+49) 89-2180-77680.
authors.forename: Sophia M
authors.initials: SM
authors.lastname: Manolikakes
authors.forename: Mario
authors.initials: M
authors.lastname: Ellwart
authors.forename: Christos I
authors.initials: CI
authors.lastname: Stathakis
authors.forename: Paul
authors.initials: P
authors.lastname: Knochel
mesh_terms: D002384:Catalysis; D060326:Chemistry Techniques, Synthetic / Q000379:methods; D015394:Molecular Structure; D009942:Organometallic Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D010421:Pentanoic Acids / Q000138:chemical synthesis / Q000737:chemistry*; D015032:Zinc / Q000737:chemistry*
chemical_list: D009942:Organometallic Compounds; D010421:Pentanoic Acids; C005566:pivalic acid; D015032:Zinc
keywords: copper; magnesium; metalation; synthetic methods; zinc