Light-Activated Copper(II) Complexes for Efficient anti-Markovnikov Alkene Hydration

The selective conversion of alkenes into alcohols is a cornerstone of modern chemical synthesis, underpinning the production of pharmaceuticals, functional materials, and fine chemicals. However, conventional acid-catalyzed hydration reactions typically follow Markovnikov’s rule, yielding secondary or tertiary alcohols. Achieving the complementary anti-Markovnikov hydration, where water adds to form primary alcohols, has long remained a challenge in organic chemistry. Although photocatalytic strategies have emerged as promising alternatives, they are limited only to activated substrates, leaving a significant gap in practical and sustainable solutions.

To address this challenge, a team of researchers led by Professor Tomoya Miura from the Division of Applied Chemistry, Okayama University, Japan, along with Dr. Naoki Oku from the Division of Applied Chemistry, Okayama University, Japan, and Dr. Hiroshi Ikeda from the Department of Applied Chemistry and The Research Institute for Molecular Electronic Devices, Osaka Metropolitan University, Japan, have developed a novel photocatalytic system based on copper(II), an inexpensive and widely available metal. By carefully designing a heteroleptic copper(II) complex that can be activated under visible light, they achieved a system with remarkably high oxidative power. The study was published in Volume 17 of the journal Nature Communications on February 21, 2026.

“We developed a new photocatalytic system with enhanced oxidative capability aimed to achieve anti-Markovnikov hydration of a broad range of alkenes, including aliphatic ones,” says Prof. Miura.

The results demonstrate that the copper(II)-based catalyst can efficiently convert a broad range of alkenes into alcohols with high selectivity. Unlike typical copper complexes that undergo rapid excited-state deactivation, the copper(II)-based catalyst exhibits a sufficiently long-lived excited state to enable intermolecular single-electron transfer. Notably, the system shows excellent performance not only for aromatic alkenes but also for challenging aliphatic substrates, which are typically difficult to activate. The reaction proceeds under mild conditions and avoids harsh reagents, making it suitable for sensitive and complex molecules. In addition, it enables late-stage functionalization of natural products and pharmaceutical derivatives, highlighting its practical utility in modifying advanced molecular structures without disrupting existing functional groups.

“Our method employs an inexpensive and readily available copper-based photocatalyst and enables selective synthesis of anti-Markovnikov alcohols from alkenes. It can be extended to other transformations, including intramolecular cyclization reactions and anti-Markovnikov addition of nucleophiles other than water, such as alcohols and azoles. This broad applicability highlights its potential as a general platform for diverse molecular transformations,” says Prof. Miura.

Mechanistic investigations revealed that the reaction proceeds through radical intermediates generated by photoinduced single-electron oxidation of alkenes. This finding is particularly significant because intermolecular single-electron transfer from photoexcited copper(II) complexes has rarely been observed. By demonstrating this reactivity, the study establishes a new design principle for photoredox catalysis based on 3d transition metals. The ability to tune the ligand environment around copper also provides flexibility in optimizing catalytic performance, offering advantages over both organic photocatalysts and precious metal systems. Moreover, the use of copper—an earth-abundant and inexpensive element—addresses key challenges related to cost, scalability, and sustainability in chemical synthesis.

“Our findings provide a new design principle for photoredox catalysis by addressing a long-standing challenge in alkene hydration. This new catalytic system based on an earth-abundant metal and operating under visible light may open new possibilities for sustainable and environmentally friendly chemical synthesis in the future,” concludes Prof. Miura.

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Reference
DOI: 10.1038/s41467-026-69807-0  

About Okayama University, Japan
As one of the leading universities in Japan, Okayama University aims to create and establish a new paradigm for the sustainable development of the world. Okayama University offers a wide range of academic fields, which become the basis of the integrated graduate schools. This not only allows us to conduct the most advanced and up-to-date research, but also provides an enriching educational experience.
Website: https://www.okayama-u.ac.jp/index_e.html

About Professor Tomoya Miura from Okayama University, Japan
Dr. Tomoya Miura is a Professor at the Division of Applied Chemistry, Okayama University, Japan. He earned his Ph.D. in Science from the Tokyo Institute of Technology in 2003. His research focuses on nanotechnology, materials science, and synthetic organic chemistry. He has received several awards including the SSOCJ Nissan Chemical Corporation Award for Novel Reaction & Method 2024 and the Nagase Foundation Award in 2022.