Iron-catalysed regioselective hydrogenation of terminal epoxides to alcohols under mild conditions

A General Regioselective Synthesis of Alcohols by Cobalt‐Catalyzed Hydrogenation of Epoxides

“…Compared to our previously disclosed iron/tetraphos catalyst system, the cobalt/triphos catalyst demonstrated a wider applicability for such substrates (Scheme 2). [12] More specifically, both monoand di-substituted terminal epoxides were suitable substrates and provided the desired anti-Markovnikov-type alcohols in good yields, tolerating amide, silyloxy, alkene, and ester substituents. Using renewable terpenes, such as (AE)-camphene (3 g), (À)-b-pinene (3 h), and (+)-aromadendrene (3 i), which are the main constituents of essential oil, the respective primary alcohols were isolated in high yields and selectivities.…”

“…Using a combination of Fe(BF 4 ) 2 •6 H 2 O and tris(2-(diphenylphosphanyl)phenyl)phosphane (tetraphos) the desired products are obtained in high yields and selectivities. [12] However, a drawback of this procedure was that only terminal epoxides were suitable [*] Dr. W. Liu [+] College of Chemistry, Chemical Engineering and Biotechnology Donghua University 201620, Shanghai (P. R. China) substrates and internal epoxides did not undergo hydrogenation to provide secondary alcohols (Figure 1 D). Herein, we describe a general and efficient non-noblemetal catalyst system [13] to enable selective hydrogenation [14] of both internal and terminal epoxides to the corresponding alcohols under mild conditions (Figure 1 E).…”

A General Regioselective Synthesis of Alcohols by Cobalt‐Catalyzed Hydrogenation of Epoxides

“…In fact, numerous terminal epoxides, including several natural‐product derivatives (steroids, terpenoids, and sesquiterpenoids), were effectively hydrogenated to the linear alcohols with high regioselectivities. Compared to our previously disclosed iron/tetraphos catalyst system, the cobalt/triphos catalyst demonstrated a wider applicability for such substrates (Scheme ) . More specifically, both mono‐ and di‐substituted terminal epoxides were suitable substrates and provided the desired anti‐Markovnikov‐type alcohols in good yields, tolerating amide, silyloxy, alkene, and ester substituents.…”

“…Independently, our group developed the first non‐noble‐metal‐catalyzed hydrogenation of terminal epoxides to give primary alcohols. Using a combination of Fe(BF 4 ) 2 ⋅6 H 2 O and tris (2‐(diphenylphosphanyl)phenyl)phosphane (tetraphos) the desired products are obtained in high yields and selectivities . However, a drawback of this procedure was that only terminal epoxides were suitable substrates and internal epoxides did not undergo hydrogenation to provide secondary alcohols (Figure D).…”

Tuning regioselective oxidation toward phenol via atomically dispersed iron sites on carbon

“…Additionally, their selectivity during catalytic reactions is generally uncontrollable due to the complexity of the active iron species and the radical mediated reaction pathways. 16,17 Despite all these difficulties, ideal iron-based catalysts are still well established in nature. Iron enzymes exhibit very high levels of chemo-, regio-, and stereo-selectivity in hydrocarbon oxidation reactions, inspiring chemists to develop biomimetic iron-based catalysts to achieve remarkable activities toward C-H bond oxidation for decades.…”