Pd-Catalyzed Cascade Heck/C(sp3)–H Activation for Spirocyclopropyl Oxindoles

• DOI: 10.1021/acs.orglett.4c01017
• Publication Date: 2024-06-07T12:55:15Z
• Authors: Saleem Hafeez; Ruchi Sharma; Swati Jain; Naveen Sihag; Hemaang Bhartiya; Jitendra Singh; S. Rajagopala Reddy; M Ramu Yadav
• Keywords: Heck Reaction

We have demonstrated a Pd(0)-catalyzed Heck/C(sp3)–H activation cascade for the synthesis of spirocyclopropyl oxindoles in high yields from easily accessible ortho-bromoacrylamides. The formation oxindole is guided by an unconventional four-membered palladacycle through C(sp3)–H activation. reaction exhibits wide range substrate scope and operates efficiently with mere 0.5 mol % Pd-catalyst. In addition, use microwave conditions facilitates rapid completion reaction. Furthermore, this spirocyclopropanation strategy can be coupled [3 + 2] cycloaddition to produce spiropyrrolidine oxindoles, offering valuable approach preparation alkaloids such as (±)-horsfiline (±)-coerulescine.