Search for a full or partial Catalog Number, CAS Number or description
Your favorites Quick Order Form
Your cart is empty.
Contact Strem

'Product Blog'

It’s not MMMBop, it’s BABIBOP!

P-Chiral Bisphosphorus Ligands for Asymmetric Hydrogenation

Image1

 

Figure 1: BABIBOP ligands. Structure of ligands used for purchase and in the literature.

Transition-metal-catalyzed reactions have a history of using chiral phosphorus ligands.1 Ligands such as BINAP, BINOL, and BIPHEP have performed well in asymmetric transition-metal-catalyzed reactions.2,3 While these ligands offer a powerful tool for the synthetic chemist, they are not without their limitations.4,5 A new series of bisphosphorus chiral ligands (BABIBOPs), which possess chirality at the phosphorus center as opposed to the biaryl axis, have been recently catalogued for efficient asymmetric hydrogenation ability.6,7

The Senanayake and Kozlowski groups have successfully employed the use of these ligands in their copper-catalyzed asymmetric hydrogenations of ketones (Scheme 1).6

 

Scheme 1: Asymmetric Hydrogenation of a 2-Aryl-1-Tetralone

Image2

DFT calculations performed in this study suggest a dimeric copper hydride transition state, and ligand coordination modes similar to BINAP- and BINOL-type structures.  The Tang group has taken these BABIBOP ligands and modified the 2 and 2’ positions (Scheme 2),7 which we also offer as alkylated BABIBOP ligands (see “Product Availability” below). These modified ligands are useful in the asymmetric hydrogenation of ß-ketoesters,  affording ß-hydroxyesters in good yields and high ee’s.7

Scheme 2: Asymmetric Hydrogenation Reactions of ß-Ketoesters

Image3


Product Availability:

Image4

 

References

  1. ACS Catal., 2016, 6, 4814.
  1. Chem. Soc. Rev., 2013, 42, 497.
  1. Chem. Rev., 2016, 116, 14769.
  1. Chem. Rev., 2003, 103, 3029.
  1. Adv. Synth. Catal., 2003, 345, 15.
  1. Chem. Sci., 2018, 9, 4505.
  1. Chin. J. Chem., 2018, 36, 153.


Products mentioned in this blog and related products:

15-6410: (3S,3'S)-3,3'-Di-tert-butyl-2,2',3,3'-tetrahydro-4,4'-bibenzo[d][1,3]oxaphosphole, min. 97% (99% ee) (3S,3'S)-BABIBOP [2207601-04-3]

15-6415: (3R,3'R)-3,3'-Di-tert-butyl-2,2',3,3'-tetrahydro-4,4'-bibenzo[d][1,3]oxaphosphole, min. 97% (99% ee) (3R,3'R)-BABIBOP [2214207-73-3]

15-6420: (2S,2'S,3S,3'S)-3,3'-Di-tert-butyl-2,2'-dimethyl-2,2',3,3'-tetrahydro-4,4'-bibenzo[d][1,3]oxaphosphole, min. 97% (99% ee) (2S,2'S,3S,3'S)-DI-Me-BABIBOP [2207601-10-1]

15-6425: (2S,2'S,3S,3'S)-3,3'-Di-tert-butyl-2,2'-diethyl-2,2',3,3'-tetrahydro-4,4'-bibenzo[d][1,3]oxaphosphole, min. 97% (99% ee) (2S,2'S,3S,3'S)-DI-Et-BABIBOP

15-6430: (2S,2'S,3S,3'S)-3,3'-Di-tert-butyl-2,2'-diisopropyl-2,2',3,3'-tetrahydro-4,4'-bibenzo[d][1,3]oxaphosphole, min. 97% (99% ee) (2S,2'S,3S,3'S)-DI-iPr-BABIBOP [2207601-12-3]

15-6435: (2R,2'R,3R,3'R)-3,3'-Di-tert-butyl-2,2'-dimethyl-2,2',3,3'-tetrahydro-4,4'-bibenzo[d][1,3]oxaphosphole, min. 97% (99% ee) (2R,2'R,3R,3'R)-DI-Me-BABIBOP [2214207-74-4]

15-6440: (2R,2'R,3R,3'R)-3,3'-Di-tert-butyl-2,2'-diethyl-2,2',3,3'-tetrahydro-4,4'-bibenzo[d][1,3]oxaphosphole, min. 97% (99% ee) (2R,2'R,3R,3'R)-DI-Et-BABIBOP

15-6445: (2R,2'R,3R,3'R)-3,3'-Di-tert-butyl-2,2'-diisopropyl-2,2',3,3'-tetrahydro-4,4'-bibenzo[d][1,3]oxaphosphole, min. 97% (99% ee) (2R,2'R,3R,3'R)-DI-iPr-BABIBOP [2214207-75-5]

 

For more details on our precursors and equipment please visit the links below:

BABIBOP Ligand Kit

 

 

Return to Product Blog

Request the Strem Chemicals Catalog Bulk Quote Request Get Quarterly Updates by Email