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A series of aroxytetraphenylstiboranes, Ph4SbOAr, were obtained by the reaction of pentaphenylstiborane with phenols at ∼20 °C. The thermolysis of these compounds givesO- or o-C-phenylation products. The thermolysis of stiboranes, which incorporate aryl groups containing electron-withdrawing substituents (Ar=2,4-Br2, 2,4-Cl2, 2-NO2, 4-OPh) produces predominantly simple diaryl ethers of asymmetric structure in 58 %, 90 %, 32 %, and 60 % yields, respectively.

The rate and pathway of reactions of 3,5-di-tert-butylbenzoyl trifluoroacetate with tert-butylphenols depend on the number and position of bulky substituents determining the extent of steric shielding of the phenolic hydroxyl.

The 1,3-anionic rearrangement of aryloxysilanes is an intramolecular process that does not depend on the nature of the migrating organosilyl group but is controlled by the reactivities of the labile halogen of the aryloxysilane and of the organolithium compound in the halogen-lithium exchange reaction, which generates the silyloxyarenide ion.

1. The formation of three isomeric tetra-substituted disiloxydiphenyls in the dimerization-rearrangement of 2-trimethylsilyl-4-tert-butyl-6-triethylsilylphenoxyl is attributed to presence of two reaction sites which determine the ability of both the trimethylsilyl and triethylsilyl groups to undergo dimerization with migration. 2. The steric interaction of the ortho-organosilyl substituants in 2-trimethylsilyl-4-tert-butyl-6-triethylsilylphenoxyl alters the relative migratory capacity of these substituents relative to that in 2-trimethylsilyl- and 2-triethylsilyl-4,6-di-tert-butylphenoxyls.

1. The reaction of substituted o-bromophenoxysilanes with n-butyllithium leads to the lithium salts of substituted o-hydroxyphenylsilanes. 2. The formation of the lithium salts of substituted o-hydroxyphenylsilanes, instead of the expected aromatic organolithium compounds, is explained by anionic rearrangement, where 1,3-migration of the organosilyl groups occurs.

The character of the transformations of silicon-containing phenoxyl radicals depends on both the type of the alkyl substituent (disproportionation in the case of para-methyl group, dimerization-rearrangement in the case of para-isopropyl and para-cyclohexyl groups) and type of organosilyl substituent (dimerization-rearrangement in the case of ortho-trimethylsilyl group, disproportionation in the case of ortho-triethylsilyl and orthotriphenylsilyl groups).