Sulphur tetrafluoride and derivatives

Sulphur tetrafluoride, a colourless gas (b.p. 38° C) with toxicity of the same order as 

Aminosulphur trifluorides, which are easier to handle than SF4, can also be used for the conversion of most aldehydes and ketones to difluoromethylene derivatives numerous examples have been documented [12] (Table 3.6). A similar reaction mechanism to that for SF4 may be assumed. 

Molybdenum hexafluoride [201], chlorine monofluoride [49] and phenylsulphur tri-fluoride [202] have all been used to perform similar transformations in a limited number of cases. 

---