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Chelating phosphine ligands with an atropisomeric biaryl scaffold

Chiral MeO-BIPHEP biphosphine ligands designed for metal-catalyzed highly enantioselective hydrogenation reactions undoubtedly remains a powerful synthetic tool of the organic chemist as seen over the last couple of decades [1-2]. In many respects, the catalytic profile of the MeO-BIPHEP ligands is very similar to that of other atropisomeric diphosphines such as BINAP, P-PHOS, SYNPHOS, DIFLUORPHOS, SEGPHOS and its many analogs. The nature of the PR2 group strongly influences the catalytic performance of the metal complexes. The rhodium and ruthenium MeO-BIPHEP catalysts are highly effective for the hydrogenation of various C=O, C=C and C=N bonds and several synthetically useful C-C coupling reactions [3-5].

Listed below are chiral MeO-BIPHEP ligands that are offered in the Strem Catalog. These products are available individually for sale , as well as members of kits:

Solvias (R)-MeO-BIPHEP Ligand Kit 96-3655 includes:	Solvias (S)-MeO-BIPHEP Ligand Kit 96-3656 includes:
15-0044 R=3,5-tBu2Ph	15-0043 R=3,5-tBu2-4-OMe-Ph
15-0652 R=3,5-iPr2-4-NMe2-Ph	15-0045 R=3,5-tBu2-Ph
15-0112 R=2-furanyl	15-0653 R=3,5-iPr2-4-NMe2-Ph
15-0178 R=Ph	15-0113 R=2-furanyl
15-0654 R=iPr	15-0179 R=Ph
15-0156 R=p-Tol	15-0655 R=iPr
15-0488  R=3,5-xylyl	15-0157 R=p-Tol
	15-0159 R=3,4,5-(OMe)3-Ph
	15-0489 R=3,5xylyl

MeO-BIPHEP are promoting not only catalytic asymmetric reduction of prochiral unsaturated α- and β-ketoesters [1-2, 5], but also enantioselective Ru-catalyzed hydrogenation of tetrasubstituted olefins of cyclic β-(acylamino)acrylates [6] and Ir-catalyzed hydrogenation of heteroaromatic compounds [7-8]. MeO-BIPHEP ligand was efficiently applied for highly diastereo- and enantioselective Cu-catalyzed domino reduction/Aldol reaction of ketones with methyl acrylate [9] and reductive hydroxymethylation of styrenes and 1,3-dienes with CO₂ [10],  and also in the Pd-catalyzed highly enantioselective asymmetric hydrogenation of activated imines [11].    

Of course, MeO-BIPHEP ligands have also found applications in many other organic transformations and for more details please review the technical notes for each ligand found on our website.

References:

1.   Helv. Chim. Acta, 1991, 74, 370.
2.   Tetrahedron Lett. 1995, 36, 4801.
3.   PNAS, 2004, 101, 5799.
4.   Angew. Chem. Int. Ed. 2004, 43, 320.
5.   J. Am. Chem. Soc. 2006, 128, 5955.
6.   J. Am. Chem. Soc. 2003, 125, 9570.
7.   J. Am. Chem. Soc. 2003, 125, 10536.
8.   J. Org. Chem. 2009, 74, 2780.
9.   Angew. Chem. Int. Ed. 2006, 45, 1292.
10.   J. Am. Chem. Soc. 2017, 139, 17011.
11.   J. Org. Chem. 2007, 72, 3729.