Elaboration of a novel type of planar-chiral methylene bridged biphenols based on [2.2]paracyclophanes

Synthesis of planar chiral [2.2]paracyclophane monophosphine ligands and their application in the umpolung allylation of aldehydes

“…Calcd for C 42 H 41 ClNPPdAE1/2CH 2 Cl 2 : C, 65.86;H,5.46;N,1.81. Found: C,66.01;H,5.87;N,1.52. Compound (S)-8a.…”

Conformational rigidity and flexibility of the paracyclophane skeleton in substituted [2.2]paracyclophanes

“…The distances ∆ 1 and ∆ 2 between the atoms at the bow and stern positions and the bridging bond lengths d 1 and d 2 vary in ranges of 2.73-2.80 Å and 1.54-1.61 Å, respectively. Compounds 22-28 contain the OAlk substituent at position 4 and various substituents at position 7 (22) or 5 (23)(24)(25)(26)(27)(28). These substituents in compounds 22-28, unlike those in compounds 2-21, are not involved in intramolecular hydrogen bonds, which fix the orientation of the substituent with respect to the upper benzene ring.…”

([2]Paracyclo[2](5,8)quinolinophan-2-yl)carbinols as catalysts for diethylzinc addition to aldehydes: cooperative effects of planar and central chirality on the asymmetric induction

“…[12][13][14][15][16] Among the reported planar chiral catalysts for stereoselective dialkylzinc addition to carbonyl compounds, those derived from [2.2]paracyclophane have received increasing attention over the last few years. [17][18][19][20][21][22][23][24][25][26] This is mainly due to a substantial rigidity of the [2.2]paracyclophane backbone and to its marked stability towards oxidation and relatively high temperatures compared with the metallocene-based ligands. Recently, Rozenberg and Bräse reported the first examples of the successful application of chiral salentype as well as tridentate [2.2]paracyclophane-based N,O-ligands as catalysts in the enantioselective diethylzinc addition to aliphatic and aromatic aldehydes.…”