Thermal Methods (Boc only)

Mechanism + Description

Presumably a thermal SN1 type.
Reaction to generate the acid and isobutylene.

General comments

t-Bu esters and carbonates can be cleaved by simply heating, although the high temperatures required make this of limited utility for sensitive materials. Temperatures and reaction times can be reduced and reaction rates accelerated by the use of perfluorinated alcohol solvents or microwave heating. Note isobutylene is still generated (as per the more common acid deprotection), and so off-gassing should be considered.

Key references

Tetrahedron Letters, 2010, 51, 2244 A novel practical cleavage of tert-butyl esters and carbonates using fluorinated alcohols
Bulletin of the Korean Chemical Society, 2009, 30, 230 Solvent-free cleavage of tert-butyl esters under microwave conditions

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