Electrophilic Fluorination of Organoplatinum(II) Iodides: Iodine and Platinum Atoms as Competing Fluorination Sites

Abstract

A series of diphosphine Pt(II) aryl iodo complexes were reacted with XeF(2) to cleanly produce the corresponding Pt(II) difluoro complexes and free iodoarenes. However, when aryl ligands bearing fluoro substituents in the ortho positions were used, the formation of the corresponding Pt(II) aryl fluoro complexes was observed in the reaction with XeF(2). In the case of the Pt-C(6)F(5) complex, the products of the fluoride-for-iodide exchange were the only products observed by means of (31)P and (19)F NMR spectroscopy. The experimental and theoretical studies suggest that the formation of iodine-fluorine bond may accompany this transformation. The plausible "I-F" species could be trapped by electron-richer organoplatinum complexes to give a Pt(IV) transient which subsequently eliminates the corresponding aryl iodide. Hence, in some cases a pathway involving an attack of XeF(2) at the iodo ligand of Pt(II) aryl iodo complexes to generate I-F species can be operative in addition to or instead of the XeF(2) attack at the metal center. Our DFT studies demonstrate that the electrophilic attacks of XeF(2) at both sites, platinum and iodide, can be competitive.

The Versatile Behavior of Platinum Alkyne Complexes towards XeF2: Formation of Fluorovinyl and Fluorido Complexes

“…[11][12][13][14][15][16][17][18][19] One approach to access fluorinated buildingb locks involves metal-mediated fluorination reactions, which can often be regarded as efficient alternatives to conventional fluorination methods. [20][21][22][23][24][25][26][27][28][29][30][31][32][33][34][35][36][37][38][39] The CÀFb ond formation generally takes place either by electrophilic or nucleophilic fluorinationo ft he ligand or the metal. For the latter,m etal fluorido species can be intermediates, which then, for instance, undergo CÀFr eductive elimination.…”

Alkenyl complexes of platinum group metals: a platform for diverse reactivity patterns

“…Metal‐alkyls, alkenyls and metallacycloalkanes are very well documented species among the classical organometallic compounds, and they play a vital role in many synthetic and catalytic reactions . Ever since the preparation of the first metal‐alkenyl complex reported by Green and Smith, valuable insights into the mechanistic details of these reactions have been elucidated, including both thermodynamic and kinetic aspects .…”

“…Ever since the preparation of the first metal‐alkenyl complex reported by Green and Smith, valuable insights into the mechanistic details of these reactions have been elucidated, including both thermodynamic and kinetic aspects . The chemistry of metal‐alkenyls has experienced a notable development during the last few years, in part due to their involvement in different catalytic processes and their applications in organic synthesis, some of which can be found in the currently available literature . M‐alkenyl complexes have been postulated as key intermediates in the Fischer–Tropsch process and ethylene oligomerization reactions including the generation of thin platinum films for micro‐electronic and catalytic applications through the chemical vapor deposition (CVD) method .…”

“…Although it might be anticipated that metal‐alkenyls should display similar properties to open‐chain dialkyl transition metal complexes or metallacycles, they exhibit high reactivity due to the involvement of an olefinic double bond. The chemical properties are rather different from other known metal complexes of substituted alkyl or aryl complexes . Since then, the chemistry of metal‐alkenyls of platinum group metals (PGM) has been a current research topic in our laboratories, and a review on the exciting chemistry of metal‐alkenyls would be worthwhile.…”

“…Metal-alkyls, alkenyls and metallacycloalkanes are very well documented species among the classical organometallic compounds, and they play a vital role in many synthetic and catalytic reactions. [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16] Ever since the preparation of the first metal-alkenyl complex reported by Green and Smith, valuable insights into the mechanistic details of these reactions have been elucidated, including both thermodynamic and kinetic aspects. [17] The chemistry of metal-alkenyls has experienced a notable development during the last few years, in part due to their involvement in different catalytic processes and their applications in organic synthesis, some of which can be found in the currently available literature.…”