β-Hydroxy-tetrahydroquinolines from Quinolines Using Chloroborane: Synthesis of the Peptidomimetic FISLE-412

Abstract

A new synthetic protocol provides a simple and direct method to generate functionalized β-hydroxy-tetrahydroquinolines (THQs). Hydroboration of quinolines using chloroboranes followed by oxidation with NaBO₃ ⋅H₂ O led to the formation of functionalized β-hydroxy THQs. High regio- and diastereoselectivities were observed in α and γ substituted quinolines and the trans diastereomer of the β-hydroxy-THQ was the major isostere. This new protocol was utilized to build the novel antibody-targeted lupus peptidomimetic, FISLE-412.

Keywords: beta-hydroxy-tetrahydroquinoline; hydroboration; monochloroborane; peptidomimetics; quinoline.