Cyclopropanation tris ligands

More recently, Burgess et al. (34) used the same approach in the synthesis of a constrained phenylalanine derivative, 3-phenyl-2,3-methanophenylalanine (123). Libraries of metal complexes were screened to determine the best combination for the asymmetric cyclopropanation reaction (35). The ligands shown below were combined with AgSbFg, (CuOTf)2 PhH, RuC12(C10H14)]2, Sc(OTf)3, where tri-... 

With (l-methylethylidene)cyclopropane (1) and a naked nickel catalyst, cyclodimers are formed with methyl acrylate in a combined yield of 59% and an isomeric ratio (2/3) of 96 4. When the reaction is performed in the presence of tris(2-phenylphenyl) phosphite as modifying ligand, the combined yield increases to 89% but the selectivity drops to 85 15. ... 

Cyclopropanes. In the presence of cuprous r-butoxide complexed with tri-/i-butylphosphine, methyl a-chloropropionate and methacrylonitrile react to form the isomeric cyclopropanes (1) and (2) via organo-copper intermediates. No reaction occurs in the absence of the ligand. This reaction was carried out... 

The use of soluble rhodium(II) carboxylate catalysts in the cyclopropanation of olefins is the origin of a very detailed crystallographic and spectrophotometric SF study of dirhodium(II) tris- and tetrakis(tritolylbenzoate), and tetrakis(pivalate)/ The Rh(II)-Rh(II) moiety at the Rh2(OsC)4 core resides inside a parallelepipedic box formed by the carboxylate ligands such that smaller ligands, such as pyridine, can coordinate at either end of the dirhodium axis. The formation... 

Treatment of [Ru(Ti6-cymene)(Cl)2]2 with bis(oxazolinyl)pyridine replaces the arene ligand with the tris-chelate ligand. This product reacts with Me3SiCHN2 between 0°C and 15°C yielding a monomeric trimethylsilylcarbene complex which cyclopropanates styrene. The complex also catalyses the dimerisation of ethyl diazoacetate.205... 

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