%0 Generic
%A Yuan, Dan
%A Huynh, Han Vinh
%D 2010
%T Dinuclear and Tetranuclear Palladium(II) Complexes of a Thiolato-Functionalized, Benzannulated N-Heterocyclic Carbene Ligand and Their Activities toward Suzuki−Miyaura Coupling
%U https://acs.figshare.com/articles/dataset/Dinuclear_and_Tetranuclear_Palladium_II_Complexes_of_a_Thiolato_Functionalized_Benzannulated_N_Heterocyclic_Carbene_Ligand_and_Their_Activities_toward_Suzuki_Miyaura_Coupling/2711062
%R 10.1021/om1008023.s001
%2 https://acs.figshare.com/ndownloader/files/4387012
%K complexes 1
%K AgO 2CCF
%K bromido abstraction
%K tetranuclear NHC
%K catalyst loading
%K 3OBF
%K salt metathesis reaction
%K Pd 2S core
%K thioester function
%K sulfur bridges
%K sulfur corners
%K Pd 4S macrocylic square
%K DMSO
%X The thiolato-bridged dimeric Pd(II) benzimidazolin-2-ylidene complex 1, with a [Pd2S2] core, was conveniently prepared by the reaction of the thiol-functionalized benzimidazolium salt C and Pd(OAc)2. More straightforwardly, 1 can also be synthesized by direct treatment of the thioester-functionalized benzimidazolium salt B with Pd(OAc)2 in wet DMSO under in situ hydrolysis of the thioester function. A subsequent salt metathesis reaction of 1 with AgO2CCF3 afforded the mixed dicarboxylato/NHC analogue 2 in quantitative yield, leaving the sulfur bridges of the [Pd2S2] core unaffected despite the use of the soft Ag(I) ions. Treatment of 1 with Me3OBF4 resulted in an unexpected bromido abstraction of 1 leading to an unusual rearrangement/dimerization reaction to give the tetranuclear NHC complex 3, which features a [Pd4S4] macrocylic square with sulfur corners. These reactions demonstrate the structural diversity of the thiolato-functionalized N-heterocyclic carbene complexes and may offer access to metallo-NHC-based supramolecular architectures. A comparative catalytic study revealed the superiority of NHC/thiolato complex 2 over complexes 1 and 3 in aqueous Suzuki−Miyaura couplings at very low catalyst loading.
%I ACS Publications