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Phosphines with excellent activities in various Pd (but not only)-catalyzed coupling reactions

Solvias cataCXium ligands represent highly effective phosphines that became an essential constituent part of Palladium-catalyzed coupling processes. Very often organic transformations such as Suzuki reactions, Sonogashira couplings or Buchwald-Hartwig reactions make high demands on the employed catalyst.

The application of cataCXium catalytic systems usually based on palladium complexes with bulky, electron-rich ligands, enables significant advances in substrate scope under mild conditions with low catalyst loadings. They are stable for a period of at least 3 months in air at room temperatures in a solid state, however very unstable in air in solution.

cataCXium® C (46-0290), also known as Herrmann-Beller’s catalyst [1], is one of the best catalysts used for Heck reactions. This palladacycle complex is an air-stable material that is highly soluble in dichloromethane, medium soluble in THF and toluene. cataCXium® C is able to reach high catalyst turnover numbers with minimum catalyst loadings [2-3].

Fig. 1. CataCXium® C – Herrmann-Beller’s catalyst

CataCXium® A includes a phosphine ligand consisting of adamantyl groups. CataCXium® A (15-0483) cataCXium® ABn (15-0038), cataCXium® AHI (15-0495) are show high activities in Suzuki [4] and Heck couplings [5], but also in Pd-catalyzed amination [5], arylation [6] and formylation of aryl bromides [7]. Also, CataCXium® A is used in Ni(0) catalyzed denitrogenative alkyne insertion reactions [8].

Fluorenederived ligand group CataCXium® F involves cataCXium® FBn (15-1072), cataCXium® FBu (15-1074), cataCXium® FPrPh (15-1076) and cataCXium® FSulf (15-1072). These 9-fluorenylphosphines were shown to be high activity catalysts in the Pd-Catalyzed Sonogashira, Suzuki, and Buchwald-Hartwig coupling reactions, not only in organic solvents but also in water [9-10].

Under the trade name CataCXium® P, products are based on pyrrole (15-2975, 15-2980, 15-3600, 15-3610), indol (15-3550, 15-3605), and imidazole (15-6362) scaffolds. These ligands form efficient catalytic systems that show outstanding catalytic performance with a Pd-promoted process [11]. For example, cataCXium® PCy (15-3610) is an excellent ligand for general synthesis of Ru-catalyzed primary amines by amination of secondary alcohols with ammonia [12]. For more details, please review corresponding technical notes.

References:

1.  Angew. Chem. Int. Ed. 1995, 17, 1844.
2.  Org. Lett., 2003, 5, 3285.
3.  Catalysts 2020, 10, 989.
4.  Angew. Chem. Int. Ed., 2000, 39, 4153.
5.  Synlett, 2000, 1589.
6.  J. Mol. Catal. A: Chem., 2002, 515, 182.
7.  Angew. Chem., Int. Ed., 2006, 45, 154.
8.  Chem. Commun., 2009, 1470.
9.  Chem. Eur. J. 2007, 13, 2701.
10.  A Europ. J. 2008, 14, 4267.
11.  ChemSusChem 2008, 1, 91.
12.  Angew. Chem. Int. Ed. 2010, 49, 8126.