New ligands have been successfully tested in enantioselective conjugate addition.
Chiral phosphoramidite ligands for asymmetric synthesis available from Strem UK
Enantioselective conjugate addition of organometallic reagents to α,β-unsaturated organic substrates is among the most important of organic transformations1,2. Substrates used in this reaction are usually α,β-unsaturated ketones, aldehydes, esters, amides, sulfoxides, or nitro compounds. Often referred to as 1,4-addition, these reactions use a variety of organometallic reagents, where non-stabilized organic moieties are directly introduced into an organic structure with high chemo- and regioselectivity transforming sp2 carbon into an sp3 one 1.
Since asymmetric synthesis plays a key role in chiral ligands, Strem is happy to introduce two new BINAP-based phosphoramidite products 15-0860 and 15-0870, that have been developed at the University of Oxford (Fig. 1).
Fig. 1. New Phosphoramidite Ligands
Using phosphoramidite ligands; 15-0860 and 15-0870, as the catalytic source of chirality, positive activity in the copper-catalyzed hydrometalation/asymmetric conjugate addition approach of alkylzirconium reagents has been reported, which provides all-carbon quaternary centers by coupling alkenes with β-substituted enones3-6 and α,β-unsaturated lactones7. More details are given in the corresponding technical notes found on Strem Chemicals web site at www.strem.com.
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15-0860: (11bS)-N-(Diphenylmethyl)-N-(i-propyl)dinaphtho[2,1-d:1',2'-f][1,3,2]dioxaphosphepin-4-amine (1637749-69-9)
For over twenty-five years, Strem Chemicals UK has been distributing high quality specialty chemicals, from Strem Chemicals, Inc, in the UK and Ireland. Strem products are used for research and development and commercial scale applications, especially in the pharmaceutical, microelectronics, chemicals and petrochemicals industries.