TY - DATA T1 - Configurationally Stable Biaryl Analogues of 4-(Dimethylamino)pyridine:  A Novel Class of Chiral Nucleophilic Catalysts PY - 1999/12/04 AU - Alan C. Spivey AU - Tomasz Fekner AU - Sharon E. Spey AU - Harry Adams UR - https://acs.figshare.com/articles/journal_contribution/Configurationally_Stable_Biaryl_Analogues_of_4-_Dimethylamino_pyridine_A_Novel_Class_of_Chiral_Nucleophilic_Catalysts/3719196 DO - 10.1021/jo991011h.s003 L4 - https://ndownloader.figshare.com/files/5810892 KW - biaryl axes KW - methyl KW - DMAP KW - rotation KW - pyridine core 16 KW - configurationally KW - chiral nucleophilic catalysts KW - Biaryls 55 KW - Chiral Nucleophilic Catalysts KW - biaryls 31 KW - Comparative HPLC studies KW - Compounds 55 KW - Novel Class KW - biaryl axis KW - Ar KW - Configurationally Stable Biaryl Analogues KW - ambient temperature KW - atropisomeric analogues KW - acyl transfer KW - pyrrolidino substituent ortho KW - novel class N2 - A short synthetic approach toward a novel class of chiral nucleophilic catalysts, the dissymmetry of which stems from restricted rotation about an Ar−Ar bond, has been developed. The key steps of the synthesis include preparation of a nucleophilic 1-methyl-2-pyrrolino[3,2-c]pyridine core 16 by ortho-lithiation and creation of the biaryl axes via Suzuki cross-coupling reactions. Comparative HPLC studies of racemization for configurationally labile biaryls 31, 38, and 43 containing 1-methyl-2-pyrrolino[3,2-c]pyridine, 4-(dimethylamino)pyridine, and 4-(1-pyrrolidino)pyridine cores, respectively, have demonstrated that a pyrrolidino substituent ortho to the biaryl axis is optimal for slowing Ar−Ar rotation. Biaryls containing all three cores have been shown to retain DMAP-like catalytic activity in the acylation of a hindered alcohol. Biaryls 55 and 56, which are configurationally stable at ambient temperature, have also been prepared via modification of configurationally labile derivatives. Compounds 55 and 56 in optically pure form should provide a useful starting point for studies on catalytic asymmetric acyl transfer using atropisomeric analogues of DMAP. ER -