757954-47-5Relevant academic research and scientific papers
Preparation of P-chirogenic phospholanes and their use in asymmetric synthesis
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Page/Page column 13, (2010/02/14)
Materials and methods for preparing P-chirogenic monophospholanes and bisphospholanes are disclosed. The methods employ stereoselective cyclization to generate the phospholane rings followed by pyramidal inversion to access a variety of P-chirogenic phosp
Stereoselective cyclization and pyramidal inversion strategies for P-chirogenic phospholane synthesis
Hoge, Garrett
, p. 9920 - 9921 (2007/10/03)
Preparation of P-chirogenic mono- and bisphospholanes is reported. The demonstrated method employs a stereoselective cyclization of cyclic sulfates with primary phosphines in the presence of base to generate "cis" or "cis/cis" P-chirogenic phospholanes followed by heat-induced pyramidal inversion to provide "trans" or "trans/trans" P-chirogenic phospholanes. A rhodium complex of one "trans/trans" phospholane is applied to the highly enantioselective asymmetric hydrogenation of a substrate precursor to the pharmaceutical candidate pregabalin. Copyright
A comparison of monocyclic and bicyclic phospholanes as acyl-transfer catalysts
Vedejs,Daugulis,Harper,MacKay,Powell
, p. 5020 - 5027 (2007/10/03)
The synthesis and evaluation of chiral phosphines 11, 15a, 19a, 24a, and 28a as nucleophilic catalysts for anhydride activation and kinetic resolution of alcohols is described. The relative reactivity follows the order 11a > 11b > 15a > 1 in the monocyclic series, and 24a > 19a > 28a in the bicyclic series, with an overall rate advantage of ca. 2 orders of magnitude for the bicyclic phospholanes over the monocyclic analogues. The increased reactivity of the bicyclic phospholanes for the acylation of alcohols is attributed to conformational effects and ground-state destabilization in a highly associative mechanism. Kinetic resolution data demonstrate promising enantioselectivities for 24a.
