Peter W. Rabideau

The silicon-modified metal ammonia reduction of aromatic compounds

Abstract A trimethylsilyl substituent is used to control regiochemistry in the metal-ammonia reduction of several naphthalenes, and is subsequently removed resulting in a “Misoriented Birch Reduction.”

Metal-ammonia reduction: the ring reduction of aromatic carboxylic esters

Abstract Aryl benzoates are reduced to 1,4-dihydroaromatics with Na/NH 3 in the presence of water.

Silicon modified birth reduction and reductive alkylation of polynuclear aromatics

Abstract A trimethylsilyl substituent is used to control regiochemistry, overreduction, and prevent bond cleavage during the metal/ammonia reduction of aromatic and polynuclear aromatic compounds. The trimethylsilyl group is then removed by tetrabutylammonium fluoride and replaced by either hydrogen or primary alkyl, the latter case representing overall reductive alkylation. Results are presented for naphthalene together with its 1-methyl, 2-methyl and 2-methoxy derivatives, phenanthrene and its 9-methyl and 9-ethyl derivatives, biphenyl and triptycene.

The 13C NMR conformational analysis of 9,10-dihydroanthracene monoanions

Abstract The 13C NMR chemical shifts and coupling constants for the parent and t -butyl 9,10-dihydroanthraceneyl lithiums indicate sp2 hybridization and flattened geometries.

Metal-ammonia reduction—XIV : Fluoranthene: Correlation of primary product structure with HMO theoretical prediction

Abstract Reduction of fluoranthene with lithium in liquid ammonia affords the previously undetected theoretically predicted product 3,10b-dihydrofluoranthene ( 3 ) in good yield, accompanied by minor amounts of the 2,3-dihydro isomer ( 2 ) which is shown to arise via base-catalyzed isomerization of 3 . Analogous reductive methylation of fluoranthene with methyl bromide affords either 10b-methyl-3,10b-dihydrofluoranthene ( 4 ) or 3,10b-dimethyl-3,10b-dihydrofluoranthene ( 5 ), as the major product, depending upon use of lithium or sodium. Mechanism and stereochemistry of these transformations are discussed. NMR spectral analysis of the 3,10b-dihydrofluoranthene derivatives is reported; these compounds are distinguished by an unusual 1,4-cyclohexadiene ring system locked in a relatively rigid flattened boat conformation.

Dissolving metal reduction of naphthalene coal models

Abstract The dimer, 1,2-di(4-methyl-1-naphthyl)ethane has been studied in metal-ammonia reduction as a model for the analogous polymer which has recently been reported. Both unsubstituted rings were reduced and reduction of only one ring by limiting the metal could not be accomplished. No CC bond cleavage occurred under these conditions. The dimer behaved quite differently from the monomer (1,4-dimethylnaphthalene) with respect to 1,2-dihydro and tetralin-like products.