Synthesis of chelating trimethylsiloxy diisonitrile ligands and their rhodium(1) complexes. Crystal and molecular structure of [Rh(t-BuDiNC)2]BPh4·1.5CH3CN (DiNC = chelating bidentate isonitrile ligand)

Tetrakis(tert-butyl isocyanide)copper(I) chloride monohydrate

“…A search of the Cambridge Structural Database (CSD, Version 5.26, November 2004;Allen, 2002) found 36 structures in which a transition metal is surrounded by four isonitrile ligands. Most of these structurally characterized compounds are mononuclear complexes similar to (I) (Gordon et al, 1978;Spek, 1982;Matsubayashi et al, 1982;Plummer et al, 1984;Yamamoto & Yamazaki, 1984;Ashworth et al, 1984;Krause, 1979;Goldberg et al, 1976;Kanters et al, 1989;Bois et al, 1998;Connelly et al, 1992;Ojima et al, 1991;Leach et al, 1994;Deicas et al, 1997;Crossley & Orpen, 1995), but there are also reports of transition metal complexes of diisocyanides yielding either discrete dinuclear compounds (Mann 1981;Exstrom et al, 1996) or coordination polymers (Fortin et al, 1998). Three complexes are also copper(I) compounds, with methylisocyanide (Spek, 1982), 2-methoxyisobutylisocyanide or 2-methoxycarbonyl-2-methylethylisocyanide (Deicas et al, 1997) coordinating the central metal ion.…”

Platinum(II) Complexes with Novel Diisocyanide Ligands: Catalysts in Alkyne Hydroarylation

“…After the first examples of Rh(I) complexes bearing long-chain aliphatic diisocyanide ligands, reported in the late 1970s, Angelici described the synthesis of a series of potentially chelating diisocyanides by a well-defined multistep procedure . The derivatives were produced in low overall yield but led to a series of transition metal complexes of both octahedral and square planar geometry. − In 1984 Angelici reported also the synthesis of two new examples of chelating diisocyanides obtained by a two-step process consisting in the opening of the oxazole ring of benzoxazole, after connecting two functionalized benzoxazoles to an ethylene bridge . Recently a similar approach, starting from oxazole and acetyl chlorides, has been applied to obtain new monoisocyanides by Pirrung in 2006 and then exploited by Reiser in the single-step synthesis of chiral phosphonium ester based diisocyanide ligands .…”

“…11−13 In 1984 Angelici reported also the synthesis of two new examples of chelating diisocyanides obtained by a two-step process consisting in the opening of the oxazole ring of benzoxazole, after connecting two functionalized benzoxazoles to an ethylene bridge. 14 Recently a similar approach, starting from oxazole and acetyl chlorides, has been applied to obtain new monoisocyanides by Pirrung in 2006 15 and then exploited by Reiser in the single-step synthesis of chiral phosphonium ester based diisocyanide ligands. 16 Interestingly Reiser was the first to apply diisocyanide complexes in catalysis.…”

Mono- and bi-dentate Group 6-coordinated and titanium-containing isocyanide ligands prepared from benzoxazole

“…The penta-and tetra-carbonyl chromium isocyanide complexes 1 and 2 (vide infra) formed in low yields, indicating that the tautomeric equilibrium in Scheme 1 3 cannot be reversed to afford nucleophilic CO attack. Di-and even tri-dentate isocyanide containing ligands have been prepared and studied in the groups of Angelici, 4 Hahn 5 and others. 6 Chelate formation is only possible if twelve or larger membered rings are formed.…”

“…Usually, complex formation involves the substitution of labile ligands such as of COD (COD = cyclooctadiene), NOR (NOR = norbornadiene) or η 6 -C 7 H 8 respectively, in [Rh(COD)Cl] 2 , 4 [M(CO) 4 (NOR)] (M᎐ ᎐ Cr, Mo), 5 [M(CO) 3 (η 6 -C 7 H 8 )] (M = Cr, Mo, W) 5 or by occupying the free coordination position after reaction of [M(CO) 5 I][Et 4 N] (M = Cr, W) and Ag ϩ ions. 4 All ligands are similar in that they consist of isocyanide units connected by nonmetallic atoms or groups, thus forming nonmetallic di-and tri-dentate isocyanide ligands. The chemistry of multidentate isocyanide ligands has attracted special attention, due to their potential use in nuclear medicine for the complexation of 99m Tc.…”