10.1246/bcsj.62.2093
The research focused on the rotational isomerism in fluorene derivatives, specifically examining the conformational equilibria of 9-substituted 9-(2-bromomethylphenyl)fluorene derivatives. The purpose of the study was to understand the conformational equilibria (ap-sp) of these compounds based on the kinetic data for internal rotation obtained through HNMR spectroscopy. The researchers synthesized eight 9-substituted 9-(2'-bromomethylphenyl)fluorene derivatives and compared their HNMR behavior with those of 9-substituted 9-(2'-methylphenyl)fluorene derivatives. The conclusions drawn from the study indicated that the conformational equilibria were influenced by electronic repulsion and/or steric hindrance between the 2'-bromomethyl group and the 9-carbonyl group or the fluorene ring. Chemicals used in the process included NBS (N-Bromosuccinimide), BPO (Benzoyl peroxide), carbon tetrachloride, dry hydrogen bromide, and various solvents such as CDCl3, DMSO-d6, acetone-d6, and methanol-d4 for NMR spectroscopy, as well as reagents for the synthesis and purification of the fluorene derivatives.
10.1039/c39810001264
The research investigates the benzylic functionalization of arene(tricarbonyl)chromium complexes. The study explores how the complexation of a Cr(CO)3 unit to an aromatic hydrocarbon enhances the benzylic position towards base attack, allowing the resulting carbanion to react with carbonyl compounds to produce complexed alcohols. Key chemicals involved include the arene(tricarbonyl)chromium complexes, such as (1), which react with aldehydes like formaldehyde (2) in the presence of a base like ButOK in MeSO solvent to form complexed alcohols (3). Other chemicals used in the research include (CD3)2CO for deuteriation studies, toluene-p-sulphonyl chloride for conversion of alcohols to toluene-p-sulphonates, and LiAlH4 for reduction reactions. The study also examines the stereochemical aspects of these reactions, using compounds like indanechromium(tricarbonyl) carbanion (7) and (tricarbonyl)(1-methylin- dane)chromium (8) to demonstrate stereospecificity in the addition and subsequent transformations.