Chiral Dirhodium Catalysts: A New Era for Asymmetric Catalysis

Abstract

The catalysis by dirhodium paddlewheel complexes has been an area of immense interest and extensive study over the past three decades -not only because most of the catalysts are highly stable to heat, moisture and ambient atmosphere but also for the asymmetric induction in the ylide generation. In this review, we attempt to provide an overview on the general preparation method for most homogeneous chiral dirhodium(II) catalysts that have appeared to date and their recent applications in asymmetric catalysis with iodonium ylides as carbenoid precursors.

Chiral Dirhodium(II) Carboxylates and Carboxamidates as Effective Chemzymes in Asymmetric Synthesis of Three‐Membered Carbocycles

“…Rh 2 (OAc) 4 serves as the parent compound for the synthesis of other dirhodium(II) complexes and ligand exchange procedures gave access to a wide variety of other dirhodium(II) complexes containing similar paddlewheel frameworks. 8 The introduction of chiral ligands allowed opportunities to explore, design, and synthesize various classes of chiral dirhodium(II) complexes, and the study of their catalytic activity promoted rhodium carbenoid chemistry to unprecedented levels of stereoselectivity.…”

“…8 Consequently, it is possible to control the electronic profile of the whole catalyst by changing these ligands. Development mainly focused on modifications of the electronic and/or the steric properties of the ligands, as different bridging ligands coordinated to the dirhodium axes can offer distinct degrees of charges to the metal.…”

“…2 Nowadays, the "chemzyme" description has been applied to a number of catalysts including multifunctional heterobimetallic complexes for catalytic asymmetric Michael additions, 3 chiral Lewis acid catalysts for hetero-Diels-Alder reactions, 4 cyclodextrin-based artificial enzymes, 5 achiral aluminum phenoxide derivatives as catalysts for conjugate allylation reactions, 6 and dirhodium(II) paddlewheel complexes for carbenoid transformation reactions. [8][9][10][11][12][13] Although many transition metal compounds have been recently developed, dirhodium(II) complexes are among the most attractive catalysts because of their activity and efficiency. [8][9][10][11][12][13] Although many transition metal compounds have been recently developed, dirhodium(II) complexes are among the most attractive catalysts because of their activity and efficiency.…”

Chiral Dirhodium(II) Carboxylates: New Insights into the Effect of Ligand Stereo-Purity on Catalyst Structure and Enantioselectivity

“…Chiral dirhodium(II) complexes are currently renowned as catalysts that can effectively drive a broad spectrum of reactions with superior levels of chemo-, regio-and stereo-selectivity [1][2][3][4][5][6][7][8][9][10][11][12][13][14]. Their remarkable selectivity has reached a stage where they can function as a powerful tool in building up value added molecules with complex structures [7,[15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30][31][32][33][34].…”

On the Structure of Chiral Dirhodium(II) Carboxylate Catalysts: Stereoselectivity Relevance and Insights

“…Chiral dirhodium(II) paddlewheel complexes are among the most attractive catalysts that found a widespread application in the fields of metal-nitrene and metal-carbene transformations [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15]. This immense interest originates from their exceptional ability to effectively catalyze a broad spectrum of reactions with high levels of chemo-, regio-and stereo-selectivity.…”