20539-32-6Relevant academic research and scientific papers
Synthetic utility of o-carborane: novel protective group for aldehydes and ketones
Nakamura, Hiroyuki,Aoyagi, Kouichi,Yamamoto, Yoshinori
, p. 107 - 115 (2007/10/03)
o-Carborane acts as a novel protective group of carbonyl compounds. The reaction of lithiocarborane 2, which was prepared in an essentially quantitative yield from o-carborane and n-butyllithium, with aldehydes or ketones 1 gave the corresponding addition products, o-carboranyl methanol derivatives 3, in high yields. Cleavage of o-carborane from 3 was carried out by treating 3 with catalytic amounts of KOH in THF/H20 (100/1), giving the corresponding aldehydes or ketones in good to high yields along with recovered o-carborane. Accordingly, o-carborane may be utilized as a protective group stable under protic and Lewis acid conditions. Selective alkylation of an ester group, selective reduction of an ester, and selective alkylation of a ketone in the presence of an aldehyde are accomplished by using o-carborane protective groups. - Keywords: o-Carborane; Protective group; Carbonyl compounds
Tetrabutylammonium fluoride promoted novel reactions of o- carborane: Inter- and intramolecular additions to aldehydes and ketones and annulation via enals and enones
Nakamura, Hiroyuki,Aoyagi, Kouichi,Yamamoto, Yoshinori
, p. 1167 - 1171 (2007/10/03)
The addition of o-carborane (1) to aldehydes 2 proceeded very smoothly in the presence of aqueous tetrabutylammonium fluoride (tbaf: 3 equiv) at room temperature, giving the corresponding carbinols 3 in high yeilds. The Tbaf-mediated reaction was appiled
