Special Seminar 

Kun Ho (Kenny) Park presents "Thiophene S,S-dioxides as versatile synthetic building blocks in
complex synthesis"

Abstract: The de novo synthesis of polysubstituted benzene rings is an attractive strategy that avoids
the need for lengthy synthetic manipulations of pre-formed arenes. One approach to such structures
involves cascade Diels-Alder / retro-Diels Alder chemistry, where the extrusion of small molecules
such as N2 (from pyridazines) or CO2 (from pyrones) can drive the cascade. A class of diene that has
been largely overlooked to date in such chemistry are thiophene S,S-dioxides. Thiophene S,S-dioxides
(TDOs), which are dearomatized sulfur heterocycles prepared by oxidation of thiophenes, serve as
highly effective substrates for inverse electron-demand Diels-Alder reactions. This seminar will
outline my recent efforts to utilize TDOs in target-oriented synthesis, leading to comprehensive
syntheses of the illudalane sesquiterpene1 and Strychnos indole alkaloid families.2 These investigations
prompted the creation of the first asymmetric cycloadditions involving TDOs, employing a chiral
auxiliary.

Biography: Kun Ho (Kenny) Park has a background in research that focuses on the development of efficient synthetic route,
utilizing newly developed methods with the goal of streamlined synthesis of various biologically active compounds. He completed his undergraduate studies at the University of California at Berkeley, where he earned a B.S. in chemistry, before pursuing a master's degree at Seoul National University. At Seoul National University, he worked in Professor David Yu-Kai Chen's laboratory on the total synthesis of complex alkaloids. Following his master's, he began a DPhil program at the University of Oxford. During his time there, he worked with Professor Edward Anderson on developing a novel diene motif, thiophene-S,S-dioxides, for use in an inverse-electron demand cycloaddition reactions. He is currently working as a postdoctoral researcher at Memorial Sloan Kettering Cancer Center in the lab of Professor Derek S. Tan, focusing on the synthesis of innovative prodrugs for the novel CAR-T platform SEAKER (synthetic enzyme armed killer)