1. Ethylidene insertion in phenylsilane
2. Intermolecular chemistry of a dialkylcarbene: Adamantanylidene
3. Rearrangement of Dimethylcarbene to Propene: Study by Laser Flash Photolysis and ab Initio Molecular Orbital Theory
4. 10,10′-Dimethyltricyclo[4.3.1.01,6]deca-2,4-dieneA solution of methyllium in ether (1.4 M, 48 mL) was added dropwise under argon at −50°C to a magnetically stirred solution of copper(I) iodide (6.4 g, 33.6 mmol) in dry THF (120 mL). The mixture was allowed to warm up to 0°C, stirred for 5 min, and cooled to −60°C. Then a solution of 10,10′-dimethyltricyclo[4.3.1.01,6]deca-2,4-diene (0.96 g, 3.3 mmol) in dry THF (20 mL) was added dropwise over 5 min. The mixture was stirred at −40°C for 3 h then iodomethane (4.35 mL, 70 mmol) was added dropwise. The mixture was allowed to warm up to 1–5°C and was stirred at this temperature for 16 h, concentrated on the rotary evaporator at room temperature, poured into a 15% solution of ammonium hydroxide (150 mL), extracted with light petroleum ether, washed with water, dried over magnesium sulfate, evaporated and decolorized by passing through a short silica gel column using light petroleum ether as the eluent. Yield 0.352 g (66.3%), colorless liquid: 1H NMR (500 MHz, C6D6) δ 0.53 (s, 3H), 1.26 (s, 3H), 1.40 (m, 1H), 1.74 (m, 3H), 1.99 (m, 2H), 5.85 (dd, J=7.3, 2.7 Hz, 2H), 5.91 (m, 2H); 13C NMR (125 MHz, C6D6) δ 16.70, 16.77, 17.17, 27.15, 33.39, 47.75, 120.91, 127.52; λmax 250 nm; IR, cm−1 (neat) 3026, 2949, 2871, 1640, 1452, 1374, 1385, 757; HRMS calcd for C12H16 160.1252, found 160.1298.Dimethylcarbene trapping experimentsSolutions of 10,10′-dimethyltricyclo[4.3.1.01,6]deca-2,4-diene (3–6 mg) in dry deoxygenated solvents (0.25 mL) under argon were irradiated with 254 nm light in a rayonet reactor at 4–8°C until complete conversion of the starting material as confirmed by GC (2–26 h). Yields of dimethylcarbene were determined from calibrated GC data by measuring the yield of indane formed upon irradiation. Yields of insertion products were based on the yield of dimethylcarbene as calculated from the GC data using calibration with the corresponding reference compounds purchased from Aldrich.
5. Cyclopropylmethylcarbene