Oxidation of Propargylic Alcohols with a 2‐Quinoxalinol Salen Copper(II) Complex and tert‐Butyl Hydroperoxide. Issue 8 (28th January 2013)

• Record Type: Journal Article
• Authors: Weerasiri, Kushan C.; Gorden, Anne E. V.
• Is Part Of: European journal of organic chemistry. Issue 8(2013)
• Page Start: 1546
• Page End: 1550
• Publication Date: 2013-01-28
• Subjects: Synthetic methods -- Copper -- Oxidation -- Homogeneous catalysis -- ­Alcohols -- Alkynes; Chemistry, Organic -- Periodicals; Organic compounds -- Synthesis -- Periodicals; Bioorganic chemistry -- Periodicals; Chemistry, Physical organic -- Periodicals; 547
• DOI: 10.1002/ejoc.201201394
• Languages: English
• ISSNs: 1434-193X

Abstract

Abstract: The copper(II) complex of 2‐quinoxalinol salen (salqu) is an efficient catalyst for the selective oxidation of propargylic alcohols to yield the corresponding α, β‐acetylenic carbonyl compounds when used in combination with the oxidant tert ‐butyl hydroperoxide (TBHP). Excellent yields (up to 99 %) are achieved for a variety of propargylic alcohols within 1 h of reaction time. The (salqu)copper(II) complex with TBHP can be used with propargylic alcohols that contain alkyl groups in the α‐position, which can be difficult to oxidize selectively with other commonly available methods. By using this catalytic protocol, excellent selectivity was also achieved for the oxidation of propargylic alcohols over that of isolated hydroxy groups, triple bonds, or propargylic methylene groups. Abstract : The 2‐quinoxalinol salen copper(II) complex is an efficient catalyst when used with tert ‐butyl hydroperoxide for the oxidation of propargylic alcohols to yield the corresponding carbonyl compounds. This catalytic system provides excellent selectivity for the reaction with propargylic alcohols, and high yields (up to 99 %) are achieved within 1 h and with 1 mol‐% of catalyst loading.