Zirconium-Mediated Synthesis of Arsaalkene Compounds from Arsines and Isocyanides

Abstract

An atom-economical synthesis of arsaalkenes via a net coupling of aryl arsines with aryl or alkyl isocyanides at zirconium is presented. Reaction of zirconium arsenido complexes (N3N)ZrAsHAr [N3N = N(CH2CH2NSiMe3)3(3-); Ar = Ph, (2) Mes (3)] with aryl and alkyl isocyanides yields arsaalkene products of the general form (N3N)Zr[NRC(H)═As(Ar)]. Two examples (5: R = Mes, Ar = Ph; 6: R = CH2Ph, Ar = Mes) were structurally characterized. Observation of intermediates in the reaction and structural characterization of the previously reported 1,1-insertion product benzylisocyanide with (N3N)ZrAsPh2 (8), (N3N)Zr[η(2)-C(PPh2)=NCH2Ph] (9), support the mechanistic hypothesis that these reactions occur via 1,1-insertion followed by rearrangement.

Metal-Mediated and Metal-Catalyzed Reactions of Isocyanides

“…Zirconium complexes featuring arsenido ligands react similarly. Treatment of diphenylarsenido complex 517 with CNCH 2 Ph in a benzene solution gave the expected insertion product 518 in 72% yield (RT, 15 min, toluene; Scheme ), whereas monoarylarsenido species 519 (Ar = Ph, Mes) formed arsaalkene products 520 (Et 2 O, RT or 40 °C, from 20 min to 5 h, 78–97%; Scheme ; Figure ) …”

A tripodal aminothioether ligand scaffold: Synthesis and coordination to zirconium and hafnium

“…Our initial targets were complexes of group 4 metals, particularly zirconium and hafnium. The chemistry of tren based ligands with zirconium is well established [17], and such complexes have demonstrated interesting reactivity in recent years, particularly in the area of main group-carbon bond formation [18][19][20].…”

A modular synthesis of tris(aryl)tren ligands: Synthesis, structure and lithiation chemistry

“…The ligand set binds transition metals in the +3 oxidation state, with tetradentate N4 coordination and favors a C 3 -symmetric environment around the metal center. Though many different variations of the tren ligand have been prepared, the majority of the metalation work performed to date has been on tris(silyl)tren derivatives [2,[4][5][6][7][8][9][10][11]. The tris(aryl)tren ligand set has been explored to a lesser extent [12][13][14][15][16][17][18][19], but has shown great promise in the areas of nitrogen fixation [3] and in metal cluster formation [20].…”