The constitution of the Grignard reagent Part II

Abstract

Association numbers of magnesium compounds in tetrahydrofuran have been investigated. One Mg‐atom is incorporated in the molecules of the Grignard reagent, of MgBr2, and of Et2Mg.

Travelling the organometallic road: a Wittig student’s journey from lithium to magnesium and beyond

“…After obtaining his PhD in Tübingen and after several years of travel and apprenticeship, the author finally continued his research in Amsterdam, where he was pleased, amongst other things, to realize that his own inclination towards organometallic compounds could smoothly be combined with certain investigations in the field of organomagnesium chemistry initiated by his predecessor Jan Coops, including highly sophisticated high vacuum techniques. 12 In the years to follow, many aspects of organomagnesium chemistry have been studied in our group such as the (unexpectedly complex) formation reaction of Grignard reagents RMgX, their structure and interaction with Lewis bases, and finally their application, in particular in organometallic synthesis. 13,14 In the course of these investigations, and for various reasons, specific attention was paid to divalent organomagnesium compounds 15.…”

Carbanions as Intermediates in the Formation of Grignard Reagents

“…General Procedures and Materials. Manipulations involving the reactions with magnesium were, unless stated otherwise, conducted in fully sealed glassware using standard high-vacuum techniques. , The magnesium used was doubly sublimed. Amounts of “total base” and Mg 2+ in organomagnesium samples were determined, after hydrolysis of a sample, by titration with HCl and EDTA, respectively. , Solvents were distilled from LiAlH 4 after predrying on KOH or in sealed glassware, distilled from sodium−potassium alloy.…”

“…Manipulations involving the reactions with magnesium were, unless stated otherwise, conducted in fully sealed glassware using standard high-vacuum techniques. , The magnesium used was doubly sublimed. Amounts of “total base” and Mg 2+ in organomagnesium samples were determined, after hydrolysis of a sample, by titration with HCl and EDTA, respectively. , Solvents were distilled from LiAlH 4 after predrying on KOH or in sealed glassware, distilled from sodium−potassium alloy. The starting materials 1-bromo-2-(bromomethyl)benzene (Aldrich), bromobenzene (Merck), 1,2-dibromobenzene (Aldrich), 2-bromo-4-methylaniline (Aldrich), 1,2-dibromoethane (Merck), MeMgBr (Aldrich), SmI 2 (Aldrich), Sm (40 mesh, Aldrich), CH 2 I 2 (Janssen), HMPA (Aldrich), and Florisil (Janssen) were commercially available.…”

1-Bromo-2,6-Bis(chloromagnesiomethyl)benzene From the Attempted Synthesis of a Doubly Benzylic 1,3,5-Tri-Grignard Reagent

“…The formation reactions of organomagnesium compounds were performed under argon or in a sealed glass apparatus [10]. The formation reactions of organomagnesium compounds were performed under argon or in a sealed glass apparatus [10].…”

“…Stirring was continued for another 2 h. Then a sample of the solution was hydrolyzed; titration with acid and complexon [10] revealed the presence of base (3.5 mmol; theoretically required for 100% of 4: 11.7 mmol) and of magnesium (5.8 mmol: theoretically required for 100% of 4: 11.7 mmol). After stirring for 15 min.…”