The synthesis of planar chiral pseudo-gem aminophosphine pre-ligands based on [2.2]paracyclophane

Abstract

The synthesis of three planar chiral pseudo-gem disubstituted [2.2]paracyclophane-derived P,N-pre-ligands is reported along with preliminary results of their activity in the amination of aryl bromides and chlorides. The pseudo-gem aminophosphines were capable of mediating the coupling reaction at a loading of 1 mol%.

Breaking paracyclophane: the unexpected formation of non-symmetric disubstituted nitro[2.2]metaparacyclophanes

“…4-Nitro[2.2]paracyclophane (4) 1 H NMR (500 MHz, CDCl 3 ) δ (ppm) 7.22 (d, J = 1.2 Hz, 1H, H-5), 6.79 (dd, J = 1.3, 7.8 Hz, 1H, H-13), 6.63–6.61 (m, 2H, H-7, H-16), 6.58 (dd, J = 1.2, 7.8 Hz, 1H, H-8), 6.53 (dd, J = 1.2, 7.7 Hz, 1H, H-15), 6.48 (d, J = 6.90 Hz, 1H, H-12), 4.02 (ddd, J =1.3, 9.6, 13.4 Hz, 1H, H-2 b ), 3.21–3.13 (m, 4H, H-9, H-10), 3.10–3.03 (m, 2H, H-1 a , H-2 a ), 2.90 (ddd, J = 7.2, 8.5, 13.3 Hz, 1H, H-1 b ); 13 C NMR (126 MHz, CDCl 3 ) δ (ppm) 149.0, 142.2, 139.9, 139.5, 137.9, 137.5, 136.6, 133.3, 133.3, 132.6, 130.1, 129.7, 36.2, 35.1, 35.0, 34.6; IR: 3009, 2928, 1694, 1531, 1516, 1336, 808 cm −1 ; mp: 158–160 °C; R f : 0.43 (10% EtOAc, 90% hexane). Data matches previous reports [ 14 ].…”

“…Not only is it the archetypal cyclophane, with a strong interaction between the two aromatic rings, but it is readily available, being a 'dimer' for the polymer parylene [6,7]. Over the last twenty years, there has been a resurgence in interest in this compound as a scaffold for the synthesis of asymmetric catalysts, energy materials, and as the basis of the study of through-space conjugation [2,[8][9][10][11][12][13][14][15][16]. There are fewer studies of [2.2]metacyclophane (2) and its derivatives.…”

“…We have been interested in the formation of substituted [2.2]paracyclophanes for a number of years [45][46][47][48][49][50][51][52], and have recently focused on 4-amino [2.2]paracyclophanes [14,[53][54][55]. For the most part, we have avoided nitration.…”

Synthesis and Basicity Studies of Quinolino[7,8-h]quinoline Derivatives

“…Given that there is clearly an opportunity to exploit this understudied system we wanted to develop chemistry that would allow access to a range of substituted quinolinoquinolines. This would permit us to pursue our interests in the coordination of small metals, catalysis, , supramolecular chemistry, − and the synthesis of unusual heterocycles. − …”