H‑Bond- and Strain-Release-Guided Photoreaction of Alkenes, p‑Quinone Methides, and Ammonium Thiocyanate

Spiro-cyclobutanes are sp3-rich molecules with applications in synthetic chemistry and drug discovery. The existing literature focuses mainly on their synthesis via the metal-catalyzed functionalization of substrates, such as spiro-cyclobutenes. In this letter, we disclose a H-bond-directed photochemical synthesis of densely substituted spiro-cyclobutanes. Moreover, a strain-release- and H-bond-directed three-component reaction of alkenes, p-quinone methide, and NH4SCN is also discussed. The reaction outcome is explained through control experiments and DFT calculations.