33356-46-6Relevant academic research and scientific papers
Arylcalcium hydrides as precursors to alkoxides and aryloxides of calcium
Dunne, John P.,Tacke, Matthias,Selinka, Carola,Stalke, Dietmar
, p. 1416 - 1425 (2003)
Calcium atoms react with +I-substituted benzene derivatives under cocondensation conditions to yield arylcalcium hydrides. With toluene, tert-butylbenzene, and trimethyl(phenyl)silane the reaction showed no selectivity for C-H activation, resulting in the formation of each of the three possible isomers, while with m-xylene the reaction resulted in selective activation of the bond meta to the CH3 groups. Treatment of (tert-butylphenyl)calcium hydride with di- and trisubstituted phenols such as 2,6-di-tert-butylphenol, 2,6-di-tert-butyl-4-methylphenol, and 2,4,6-tri-tert-butylphenol resulted in the formation of calcium aryloxides in yields > 95%. [Ca(2,4,6-tBu3C6H2O)2 (THF)3] crystallises from a THF solution as a distorted trigonal bipyramid, with two THF ligands in the trans-axial positions and the third THF ligand and both aryloxide groups in equatorial positions. The Ca-OAryl bond length was found to average at 2.181(3). A. The Ca-O-CAryl angles are almost linear, with Cal-O1-C1 and Ca1-O2-C19 being 173.9(3)° and 178.8(3)°, respectively, while the O1-Cal-O2 angle was determined as 157.04(12)°. A reaction between (tert-butylphenyl)calcium hydride and triphenylmethanol resulted in the formation of the corresponding monomeric calcium bis(alkoxide) Ca(OCPh3)2(THF)4 in 95% yield. The structure was determined as a distorted octahedron with the alkoxide ligands in a cis-equatorial arrangement. The Ca-O bond length was determined at 2.1609(17) A. The Ca-O-CAryl angle of 177.46(16)° is almost linear, while the O1-Cal-O1A angle was determined at 110.12(19)°. ( Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003).
