The design, synthesis and application of imidazolium-tagged ferrocenyl oxazoline phosphine ligands for the asymmetric 1,3-dipolar cycloaddition of azomethine ylides with nitroalkenes: ion effect for enhancing the reactivity, stereoselectivity and recyclability

Chiral Oxazolinyl Hydroxyl Ferrocene Catalysts: Synthesis and Applications in Asymmetric Reactions

“…The derived polymer‐tagged catalysts could be reused at least three times without any obvious loss of activity or enantioselectivity. In addition, functionalized ferrocene ligands with hydrophilic groups, such as ionic liquids, have been reported by our group . The modified ferrocenes also exhibit robustness during the recycling process.…”

Asymmetric Construction of Pyrrolidines Bearing a Trifluoromethylated Quaternary Stereogenic Center via CuI‐Catalyzed 1,3‐Dipolar Cycloaddition of Azomethine Ylides with β‐CF3‐β,β‐Disubstituted Nitroalkenes

“…Cu(CH 3 CN) 4 ClO 4 proved to be the most efficient catalyst Lewis acid, whereas the reaction did not proceed in the presence of Ni(ClO 4 ) 2 ⋅6H 2 O, Zn(OTf) 2 , and Sc(OTf) 3 (entries 6–8). Then, ligands, including ionic tagged oxazolinyl‐phosphine ferrocene, cinchonine‐derived thiourea, and quinine‐derived squaramide, were examined. L2 /Cu(CH 3 CN) 4 ClO 4 system afforded 85.8 % ee (entry 9), but disappointingly, both L4 and L5 did not catalyze the reaction (entries 11 and 12).…”

Architecture and synthesis of P,N-heterocyclic phosphine ligands

“…Application References pyridyl phosphines OLEDs [13] Heck coupling [14] metal organic frameworks [15] polymerization of lactides [16] alkene hydroxylation [17] addition reaction [18] ethylene oligomerization [19] synthesis of pyrazolines [20] triazolyl phosphines Suzuki cross coupling [21] asymmetric hydrogenation [22] luminescence [23] hydroformylation [24] pyrazolyl phosphines coordination polymers [25] Heck coupling [26] imidazolyl phosphines Suzuki coupling [27] hydroamination [28] OLEDs [29] ethylene oligomerization [30] amination [31] olefin metathesis [32] hydroformylation [33] pyrrolyl phosphines hydroformylation [34,35] ethylene polymerization [36] oxazolyl phosphines asymmetric cycloaddition [37] asymmetric hydrogenation [38] carbonylation of alkynes [39] allylic substitution [40] asymmetric addition [41] allylic amination [42,43] The presence of soft donor atoms such as phosphorus results in the formation of hemilabile ligands. These are multidentate ligands having hard P-donor and soft N-and/or O-donor atoms [44].…”