Advances in non‐palladium‐catalysed Stille couplings

Abstract

Stille coupling is regarded as a powerful tool in the synthesis of a wide range of functionalised C–C bonds due to the high stability, availability and broad functional group compatibility of the organostannanes. This is the first review solely focused on the role of the non‐palladium transition metals in Stille coupling with emphasis on their catalytic capacity and mechanistic details. Several transition metals including Mn, Ni, Cu, Rh, Pt, and Au are found highly efficient in the coupling with Cu having the largest reports. Importantly, Cu‐catalysed Stille couplings formed the key stages in the synthesis of therapeutic molecules like 4(S)‐11‐diHDHA and Spliceostatin derivatives. Greener protocols including reusable heterogeneous catalytic systems are promising alternatives and some have even shown dominance over Pd catalysts. This review comprises all available literature on non‐palladium Stille coupling up to June 2021.

Synthesis, Structure, and Spectroscopy of the Biscarboranyl Stannylenes (bc)Sn·THF and K2[(bc)Sn]2 (bc = 1,1′(ortho-Biscarborane)) and Dibiscarboranyl Ethene (bc)CH═CH(bc)

“…This mono-activated K­[ H-bc ] proceeded to react with the solvent molecules to afford a CC bond. The reaction was repeated without SnCl 2 , but compound 3 was not generated, suggesting that SnCl 2 is required to create the bridging alkene, possibly via a coupling mechanism similar to the Stille reaction …”

“…The reaction was repeated without SnCl 2 , but compound 3 was not generated, suggesting that SnCl 2 is required to create the bridging alkene, possibly via a coupling mechanism similar to the Stille reaction. 50 …”

“…The reaction was repeated without SnCl 2 , but compound 3 was not generated, suggesting that SnCl 2 is required to create the bridging alkene, possibly via a coupling mechanism similar to the Stille reaction. 50 X-ray Crystal Structures. Due to the rigid nature of the bc ligand, the stannylenes in 1 and 2 are constrained to a fivemembered C 4 Sn cycle.…”

Rose‐Bengal‐Photocatalyzed Cross‐Dehydrogenative Coupling Reactions under Visible Light

“…[20] The environmental cost and the need for transmetallation steps that produce stoichiometric quantities of metal salt as waste are the primary problems with many metal-catalysed cross-coupling reactions. [21][22][23][24][25][26][27][28][29][30][31][32][33][34] The 2010 Nobel Prize in Chemistry recognized the significant achievements and importance of the crosscoupling process. [35] Cross-coupling processes in organic synthesis have had a noteworthy and remarkable impact on their commendable contribution to pharmaceutical chemistry and drug development over the past two decades.…”

“…The efficiency of this pathway in terms of atom economy is due to the production of negligible quantities of side products [20] . The environmental cost and the need for transmetallation steps that produce stoichiometric quantities of metal salt as waste are the primary problems with many metal‐catalysed cross‐coupling reactions [21–34] . The 2010 Nobel Prize in Chemistry recognized the significant achievements and importance of the cross‐coupling process [35] …”