Direct Organocatalytic Asymmetric Mannich Addition of 3‐Substituted‐2H‐1, 4‐Benzoxazines: Access to Tetrasubstituted Carbon Stereocenters. Issue 17 (13th November 2013)

• Record Type: Journal Article
• Authors: Wang, You‐Qing; Zhang, Yongna; Pan, Kun; You, Junxiong; Zhao, Jin
• Is Part Of: Advanced synthesis & catalysis. Volume 355:Issue 17(2013)
• Page Start: 3381
• Page End: 3386
• Publication Date: 2013-11-13
• Subjects: Catalysis -- Periodicals; Organic compounds -- Synthesis -- Periodicals; Chemistry -- Periodicals; Chemistry, Technical -- Periodicals; Chemistry -- Periodicals; Catalysis -- Periodicals; Technology, Pharmaceutical -- Periodicals; 547.2
• DOI: 10.1002/adsc.201300654
• Languages: English
• ISSNs: 1615-4150

Abstract

<abstract abstract-type="main" xml:lang="en"> <title>Abstract</title> <p>3‐Substituted‐2<italic>H</italic>‐1, 4‐benzoxazines undergo a highly enantioselective direct Mannich reaction with acetone in the presence of an <sc>L</sc>‐proline catalyst at room temperature. The corresponding N‐heterocycles with α‐tetrasubstituted carbon stereocenters were obtained in good yields (48–92%) and excellent enantioselectivity (up to &gt;99% <italic>ee</italic>). Furthermore, a novel modification involving the diastereoselective reduction of the Mannich adduct was carried out leading to the formation of a 1, 3‐amino alcohol with a chiral tetrasubstituted carbon stereocenter in high yield.</p> <p> <boxed-text content-type="graphic" position="anchor" orientation="portrait"> <graphic position="anchor" mimetype="image" xlink:href="ark:/27927/pgg4t6scrzd" orientation="portrait" xlink:type="simple" xmlns:xlink="http://www.w3.org/1999/xlink" /> </boxed-text> </p> </abstract>