A NEW CLASS OF NETWORK-POLYMERIC CHIRAL STATIONARY PHASES

A strategy based on the use of homo bi- and multifunctional building b locks for the synthesis of a new class of network-polymeric chiral sta tionary phases has been evaluated, The key steps comprise acylation of N,N'-diallyl-L-tartardiamide (DATD) and reaction with a multifunction al hydrosilane, yielding a network polymer incorporating the bifunctio nal C-2-symmetric chiral selector. Covalent bonding to a functionalize d silica takes place during the latter process, Many of these chiral s orbents show interesting enantioselective properties toward a wide var iety of racemic solutes under normal-phase (hexane-based) conditions. The retention is mainly caused by the hydrogen-bonding ability of the analyte, which is regulated by mobile phase additives like alcohol or ether cosolvents, The most interesting chiral stationary phases, in te rms of broad enantioselectivity, were obtained from O,O'-diaryol-DATD- derivatives, particularly those containing the 3,5-dimethylbenzoyl and the 4-(tert-butyl)benzoyl moieties. Since high column efficiencies ca n be obtained with these chiral sorbents, an alpha-value of ca. 1.2 is usually sufficient to produce baseline separation. A large number of neutral as well as acidic or basic drug racemates are resolved without derivatization. (C) 1995 Wiley-Liss, Inc.