Chiral bipyridine–copper(II) complex. Crystal structure and catalytic activity in asymmetric cyclopropanation

Chiral 2,2‘-Bipyridines, 1,10-Phenanthrolines, and 2,2‘:6‘,2‘ ‘-Terpyridines: Syntheses and Applications in Asymmetric Homogeneous Catalysis

“…Kwong et al reported the synthesis of the Cu(II) complex [Cu( 67 )Cl 2 ] ( 67a ), its crystal structure, and the use of this complex and the parent ligand 67 in the cyclopropanation of a number of alkenes (Table ) . They showed that the complex 67a is not an active catalyst, but that the corresponding triflate complex, formed by treating 67a with silver triflate, was active.…”

Copper(I)−Homoscorpionate Catalysts for the Preferential, Kinetically Controlled Cis Cyclopropanation of α-Olefins with Ethyl Diazoacetate

“…The ligands employed vary from one metal to another. Thus, semicorrines, bisoxazolines, or bipyridines have been attached to copper whereas carboxylates or carboxamidates 6 are the ligands of choice with the rhodium(II) Rh 2 L 4 -type catalysts. Other ligands such as porphyrins (rhodium), pybox (ruthenium), or salen (cobalt, ruthenium , ) have also provided noticeable enantiomeric excesses.…”

Synthesis of New Chiral 2,2‘-Bipyridyl-Type Ligands, Their Coordination to Molybdenum(0), Copper(II), and Palladium(II), and Application in Asymmetric Allylic Substitution, Allylic Oxidation, and Cyclopropanation

“…Aside from these successful chiral inducers, 2,2‘-bipyridyl and 1,10-phenanthroline can be viewed as another potentially promising group since they can, a priori, be rendered chiral by appending additional substituents ( 1 , 2 in Chart ). However, despite their rich and well-documented coordination chemistry, bipyridyl and phenanthroline derivatives received relatively little attention in asymmetric catalysis to date and became emerging only recently. − Among the sporadic entries into this realm are the bipyridyl derivatives 3 − 7 . While the monoterpene origin of ligands 5 − 7 can easily be recognized and their synthesis is relatively straightforward, − 3 and 4 are products of a “purely synthetic” effort: thus, for example, 4 was synthesized via a lengthy procedure, which itself required a rather elaborate synthesis of another chiral catalyst to be employed in one of the steps …”