4109-95-9Relevant academic research and scientific papers
Spectroscopic Characterization of Heterohalogenic Dihalomethylzinc Carbenoids: Application to a More Efficient Chlorocyclopropanation Reaction
Taillemaud, Sylvain,Charette, André B.
supporting information, p. 83 - 92 (2022/01/04)
Dihalomethylmetal reagents are important species that can be used in halocyclopropanation reactions (metal = zinc) as well as in alkenyl halide synthesis. When trihalomethanes containing two or more different halogen atoms are used to prepare zinc carbenoids, several species can be formed through a halogen scrambling process. This affects which halocyclopropane, or haloalkene, is generated in the subsequent reaction. In the first part of the paper, we report an extensive characterization of zinc dihalocarbenoids by NMR to identify the major species formed when various di-and trihalomethane reagents are used as carbenoid precursors. In the second part of the paper, a direct application of this information enabled the development of a highly efficient chlorocyclopropanation reaction of allylic alcohols from inexpensive and accessible precursors.
AN INEXPENSIVE INFLUENCE MODIFICATION OF THE SIMMONS-SMITH REACTION: THE FORMATION OF BROMOMETHYLZINC BROMIDE AS STUDIED BY NMR SPECTROSCOPY
Fabisch, Bodo,Mitchell, Terence N.
, p. 219 - 222 (2007/10/02)
Bromomethylzinc bromide, prepared from zinc metal and methylene bromide in tetrahydrofuran, gives moderate to good yields of cyclopropanation product when treated with olefins, thus providing an inexpensive alternative to the Simmons-Smith procedure.An NMR study of the reaction between metallic zinc and methylene bromide has been carried out: in addition to bromomethylzinc bromide and dimethylzinc, two further species were observed and tentatively identified as bis(bromomethyl)zinc a di- or tri-zinc compound.
