Planar chiral imidazolium salts based on [2.2]paracyclophane in the asymmetric rhodium-catalyzed 1,2-addition of arylboronic acids to aldehydes

Synthesis of a Ni Complex Chelated by a [2.2]Paracyclophane-Functionalized Diimine Ligand and Its Catalytic Activity for Olefin Oligomerization

“…Mono-substituted [2.2]paracyclophane has a double-decker structure with a chiral center in the molecule. The transition metal complexes with the paracyclophane-containing nitrogen ligand, such as a Ti-Salen complex [ 57 ] and Au and Rh complexes with N -heterocyclic carbene (NHC) ligands [ 58 , 59 , 60 ], were employed as the catalyst for stereoselective reactions. We conducted condensation of acenaphtenequinone with two molar equivalents of amino[2.2]paracyclophane with expecting formation of a diimine ligand having two [2.2]paracyclophanyl substituents.…”

The synthesis of substituted amino[2.2]paracyclophanes

“…47,49 The generality of the methodology was confirmed by preparing a number of disubstituted paracyclophanes starting with the known pseudo-gem amino ester 15, 16 and amino bromide 12. 33,50,51 Exploiting the transannular effect, the pseudo-gem aldehyde 13 17 could be prepared by directed Rieche formylation of ester 12 (Scheme 3). 52 Oxime (14) formation followed by the oxidation-rearrangement sequence gave the desired amine 15 in moderate to good yield.…”

“…The palladium-mediated Buchwald-Hartwig amination 27 of (pseudo)halides offers a direct route to aminoparacyclophanes. 15,28,29,[30][31][32][33][34][35] It would be reasonable to think this was a general and reliable route but such aminations are substrate specific. For example, the optimum ligand to couple 4-bromo [2.2]paracyclophane with benzylic amines is BINAP 30 yet this ligand fails 32 to give satisfactory yields when anilines are used.…”

Synthesis of New Chiral Benzimidazolylidene–Rh Complexes and Their Application in Asymmetric Addition Reactions of Organoboronic Acids to Aldehydes

“…Since then, considerable efforts have been made in this type of reaction [23][24][25][26][27][28][29][30]. However, examples of using chiral N-heterocycliccarbenes in the ligand-catalyzed asymmetric arylation of aldehydes are rare [31][32][33][34][35]. Therefore, developing new chiral N-heterocycliccarbene ligands for the asymmetric 1,2-addition of arylation of aldehydes are rare [31][32][33][34][35].…”

“…However, examples of using chiral N-heterocycliccarbenes in the ligand-catalyzed asymmetric arylation of aldehydes are rare [31][32][33][34][35]. Therefore, developing new chiral N-heterocycliccarbene ligands for the asymmetric 1,2-addition of arylation of aldehydes are rare [31][32][33][34][35]. Therefore, developing new chiral N-heterocycliccarbene ligands for the asymmetric 1,2-addition of organoboronic acid to aldehydes is an important synthetic goal.…”