Quantitative syntheses of permethylated -1,10-RCBMe (R = H, Me) carboranes. Egg-shaped hydrocarbons on the Frontier between inorganic and organic chemistry

Electrophilic methylation of the closo -1,10-R 2 C 2 B 8 H 8 ( 1 ) (R = H or Me) dicarbaboranes at higher temperatures or thermal rearrangement of the 1,6-R 2 C 2 B 8 Me 8 ( 3 ) compounds at 400-500 °C generated the B-permethylated derivatives closo -1,10-R 2 C 2 B 8 Me 8 ( 2 ) in quantitative (>95%) yields. The compounds exhibit extreme air stability as a consequence of a rigid, egg shaped hydrocarbon structures incorporating inner 1,10-C 2 B 8 carborane core. Reported are procedures leading to highly stable egg-shaped hydrocarbons with inner closo -1,10-C 2 B 8 carborane core inside the methyl sheath.