Microwave Chemistry in Silicon Carbide Reaction Vials: Separating Thermal from Nonthermal Effects

Figure. Heating rates for 3 mL samples of hexane (tand=0.02),[3]

MeCN (tand=0.062),[3] EtOH (tand=0.941),[3] and 1-butyl-3-methylimidazoliumhexafluorophosphate ([bmim]PF6, tand>1)[8] at 130 Wconstant magnetron power in a 10 mL Pyrex vial (a), and in a custom-madeSiC vial (b). Single-mode microwave irradiation, magneticstirring, internal fiber-optic temperature measurement.[6]

Figure. Comparison of heating rates for 3 mL samples of hexane (tan δ = 0.02), MeCN (tan δ =0.062),EtOH (tan δ = 0.941), and bmimPF6, tan δ >1) at 130 W constant microwave power in Pyrex and SiC vials. Single-mode microwave irradiation, magnetic stirring, internal fiber-optic temperature measurement (Monowave 300).

Figure. Internal fiber-optic temperature profiles for the solvent-freesynthesis of the ionic liquid [bmim]Br using Pyrex and SiC reactionvials. Experiments were performed using an IR-controlled set temperatureof 1008C on a 10.6 mmol scale (1.02 equiv of BuBr)

a) Mizoroki-Heck reaction

b) Alkylation of PPh3

c) Newman-Kwart

d) Claisen rearrangement

Newmqn-Kwart rearrangment

Claisen rearrangment