Search

The difluoromethyl phosphonate motif plays a crucial role in the development of bioactive molecules as it is considered as a phosphate bioisoster. Since 2010, a renewal of interest to enlarge the panel of reactions to access these difluoromethylated phosphonate-containing molecules has been witnessed. This Concept article charts the recent progress that has been made.

A general and efficient access to aryl, heteroaryl, vinyl and alkynyl difluoromethylphosphonates is described. The developed methodology using TMSCF2PO(OEt)2, iodonium salts and a copper salt provided a straightforward manifold to reach these highly relevant products. The reaction proved to be highly functional group tolerant and proceeded under mild conditions, giving the corresponding products in good to excellent yields. This method represents the first general synthetic route to this important class of fluorinated scaffolds, which are well-recognized as in vivo stable phosphate surrogates.

The reaction of furanose and pyranose derivatives with optically active sulfinamidine (II) gives the title compounds (III) and (VII), respectively.

Difluoromethylated arenes are scaffolds of great interest. We report herein a mild and general method for the introduction of the CF2PO(OEt)2 moiety into arenes. The CuCF2PO(OEt)2 species, which is generated in situ from the corresponding silylated derivatives, in combination with aryl diazonium salts furnished the highly valuable aryl difluoromethylphosphonates in moderate to good yields. This represents the first general method to introduce difluoromethylphosphonates under mild conditions.

The first direct introduction of a functionalized fluorinated moiety into electron-rich arenes by a copper-catalyzed radical-free process is reported.

Highly functionalized tri- and tetra-substituted alkenyl triflates are prepared from alkynes and vinyl(aryl) or diaryliodonium salts.

Ring-opening with benzoyl chloride or electrophiles (IV) is studied to yield differently protected β-hydroxy vinyl ethers.

The process can be controlled by changing the conditions and thus affords the different types of title compounds.

Methyl 6-O-alkyl-glucopyranosides were obtained in excellent yield from methyl 6-deoxy-6-iodoglucopyranoside and the appropriate alcohol in the presence of chlorine.

Treatment of tetraaryltin (1) in toluene with SnCl4 at room temperature gave the corresponding aryltin chloride (2). By quenching the reaction mixture with thiols, aryltin sulfides (3) (5a) (5b) and (7) have been isolated in good yields.

Summary A series of alkyl (aryl) thio organotin compounds were synthesized as potential trypanocidal drugs. These derivatives were prepared by the treatment of alkyl (or aryl) tin chlorides or oxides with thiols. Compounds were evaluated for trypanocidal activity using in vitro cultures of Trypanosoma equiperdum . Their efficiency for killing the parasites appeared to be under control of both the alkyl (or aryl) part of the molecule and the thio moiety. Several of the synthesized compounds exhibited a high in vitro levels of activity compared with the arsenic derivatives used for chemotherapy.

The Suzuki cross-coupling in the presence of trans-TPS offers a convenient synthesis of 2-benzylindoles.

While achieving high Curie temperatures (above room temperature) in diluted magnetic semiconductors remains a challenge in the case of well controlled homogeneous alloys, several systems characterized by a strongly inhomogeneous incorporation of the magnetic component appear as promising. Incorporation of manganese into germanium drastically alters the growth conditions, and in certain conditions of low temperature Molecular Beam Epitaxy it leads to the formation of well organized nanocolumns of a Mn-rich material, with a crystalline structure in epitaxial relationship with the Mn-poor germanium matrix. A strong interaction between the Mn atoms in these nanocolums is demonstrated by x-ray absorption spectroscopy, giving rise to a ferromagnetic character as observed through magnetometry and x-ray magnetic circular dichroism. Most interesting, intense magneto-transport features are observed on the whole structure, which strongly depend on the magnetic configuration of the nanocolumns.