Sandmeyer reaction Subject

With the ArH ArTlX2 Arl reaction sequence available as a rapid and reliable probe for aromatic thallation, a detailed study was undertaken of the various factors affecting orientation in this electrophilic metallation process (153). The results, which are summarized below, demonstrate that aromatic thallation is subject to an almost unprecedented degree of orientation control coupled with the ease with which thallium can then be displaced by other substitutent groups (this aspect of the synthetic exploitation of aromatic thallation is discussed in detail below), the sequential processes of thallation followed by displacement represent a new and versatile method for aromatic substitution which both rivals and complements the classic Sandmeyer reaction. 

In this nexus, the groups of van Lier and Torres independently reported in 1997 the preparation of a highly soluble A3B-type zinc(II) Pc, where A represents substituted tert-butyl isoindolines, whereas B stands for an iodine-containing unit (Fig. 3). The former group started with the preparation of mononitro Pc 1 obtained through statistical condensation of 4-nitrophthalonitrile and 4-fert-butylphthalonitrile in the presence of zinc acetate [41], Subsequent reduction of Pc 1 provided the amino function which was then subjected to a Sandmeyer reaction to furnish the targeted... 

The neurotoxic quaterpyridine natural product nemertelline was successfully synthesized by S. Rault et al. using a Suzuki cross-coupiing as the key step. The boronic acid coupling partner, required for the Suzuki reaction, was prepared by first subjecting 3-amino-2-chloropyridine to the conditions of the Sandmeyer reaction followed by a lithium-halogen exchange and trapping the lithiopyridine derivative with triisopropylborate. 

Subjection of 3-chloro[U- C]aniline to a second CuCl-mediated Sandmeyer reaction... 

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