Diazoalkane complexes of ruthenium with tris(pyrazolyl)borate and bis(pyrazolyl)acetate ligands

Pentamethylcyclopentadienyl Half-Sandwich Diazoalkane Complexes of Ruthenium: Preparation and Reactivity

“…Conversely, the N(1)–N(2)–C(11) bond angle is 164.1(4)°, more acute than those found in the above-mentioned η 5 -indenyl, 171.2(3)°, the Cp substituted compound, 173.9(6)°, and the 9-diazofluorene ruthenium complex Ru­{NNC­(C 12 H 8 )}­(PNP)­Cl 2 [170.1(3)°] . Of course, it is also far from the almost linear value found for the Tp derivative, 178.2(4)° . The bond distances at the diazo moiety, Ru–N(1) of 1.950(3) Å, N(1)–N(2) of 1.161(4) Å and N(2)–C(11) of 1.296(4) Å, are virtually the same values found in the above-mentioned 9-diazofluorene ruthenium complexes (η 5 -Ind)­RuP 1 P 2 ­{NNC­(C 12 H 8 )} and Ru­[NNC­(C 12 H 8 )}­(PNP)­Cl 2 , or even in CpRuP 1 P 2 ­[NNC­(Ph)­Tol], so that a double bond between the nitrogen atoms and also N(2) and C(11) can be proposed.…”

“…The most interesting characteristic of 2c is the coordination mode of the 9-fluorenediazo ligand. It should be noted that the Ru–N(1)–N(2) bond angle depends on the ancillary ligand, so that the tris­(pyrazolyl)­borate derivative (Tp) shows an angle close to 130°, but η 5 -indenyl or Cp derivatives have angles between 150 and 160°. The new Cp* derivative 2c should be included in the latter group, with a Ru–N(1)–N(2) bond angle of 153.1(3)°.…”

“…This result was rather unexpected, since η 5 -C 5 Me 5 diazo derivatives 1 – 4 react so easily with H 2 O that 1,2-diazene complexes 6 – 9 slowly form, even with traces of water present in not strictly anhydrous solvents. Also unreactive to hydrolysis are the half-sandwich indenyl [Ru­(η 5 -C 9 H 7 )­(N 2 CAr1Ar2)­{P­(OR) 3 }­(PPh 3 )]­BPh 4 and tris­(pyrazolyl)­borate derivatives [Ru­(Tp)­(N 2 CAr1Ar2)­{P­(OR) 3 }­(PPh 3 )]­BPh 4 , highlighting the peculiar properties of the pentamethylcyclopentadienyl ligand, which, in the half-sandwich fragment [Ru­(η 5 -C 5 Me 5 )­{P­(OR) 3 }­L] + (L = phosphite or PPh 3 ), can activate the coordinated diazoalkane toward hydrolysis.…”

“…2g Of course, it is also far from the almost linear value found for the Tp derivative, 178.2(4)°. 32 The bond distances at the diazo moiety, Ru−N(1) of 1.950(3) Å, N(1)−N(2) of 1.161(4) Å and N(2)−C( 11) of 1.296(4) Å, are virtually the same values found in the above-mentioned 9diazofluorene ruthenium complexes (η 5 -Ind)RuP 1 P 2 {NNC-(C 12 H 8 )} 33 and Ru[NNC(C 12 H 8 )}(PNP)Cl 2 , 2g or even in CpRuP 1 P 2 [NNC(Ph)Tol], 6a so that a double bond between the nitrogen atoms and also N(2) and C( 11) can be proposed.…”

Reactions of Iron(II) Complexes Supported by Tripodal Amido-Phosphine-Amido Ligands with Diazo Compounds

“…[6][7][8][9][10] Consequently, there are great interests on the sythesis, structural feature, and reactivity of transition-metal diazoalkane complexes. The known transition-metal diazoalkane complexes are dominated by the complexes of cobalt, nickel, and ruthenium, [11][12][13][14][15][16] whereas the diazoalkane complexes of iron are scarce, which form a sharp contrast to the soaring research interest on iron-catalyzed carbenetransfter reactions. [17] The limited examples of iron diazoalkane complexes include the bis(imino)pyridine complex [(PDI)Fe(η 1 -N 2 CH-SiMe 3 )] (A in Chart 1), [18] the tris(pyrrolido)ethane iron complex [(tpe)Fe(η 1 -N 2 CPh 2 )][Li(THF) 4 ] (tpe＝tris(5-mesitylpyrrolyl)ethane, B), [19] the β-diketiminate iron complex [L Bu-t Fe(η 1 -N 2 CPh 2 )] (L Bu-t ＝ [(DippNCBu t ) 2 CH] -, C) [20] , the cyclopentadienyliron complexes [(η 5 -C 5 H 5 ) Fe(η 1 -N 2 C-Ar 1 Ar 2 )(P-P)]BPh 4 (P-P＝1,2-bis(diphenylphosphine)ethane, 1,3-bis(diphenylphosphine)propane; Ar 1 ＝ Ar 2 ＝ Ph; Ar 1 ＝Ph, Ar 2 ＝p-tolyl; Ar 1 Ar 2 ＝C 12 H 8 , D), [21] as well as the side-on type diazo complexes [(PDI)Fe(η 2 -N,N-N 2 C-Ph 2 )] (E) [22] and [L Bu-t Fe(η 2 -N,N-N 2 CPh 2 )K(OEt 2 )] 2 (F) [20] .…”