Highly Efficient Synthesis of Heterocyclic and Alicyclic β2‐Amino Acid Derivatives by Catalytic Asymmetric Hydrogenation. Issue 9 (17th June 2013)

• Record Type: Journal Article
• Authors: Li, Lanning; Chen, Bin; Ke, Yuanyuan; Li, Qing; Zhuang, Yue; Duan, Kun; Huang, Yichun; Pang, Jiyan; Qiu, Liqin
• Is Part Of: Chemistry, an Asian journal. Volume 8:Issue 9(2013:Sep.)
• Page Start: 2167
• Page End: 2174
• Publication Date: 2013-06-17
• Subjects: Chemistry -- Periodicals; 540.5
• DOI: 10.1002/asia.201300339
• Languages: English
• ISSNs: 1861-4728

Abstract

<abstract abstract-type="main" xml:lang="en"> <title>Abstract</title> <p>A valuable class of new heterocyclic and alicyclic prochiral α‐aminomethylacrylates has been conveniently synthesized through a three‐step transformation involving a <named-content id="d416e1429" content-type="reactionType" xlink:type="simple" xmlns:xlink="http://www.w3.org/1999/xlink">Baylis–Hillman reaction</named-content>, <named-content id="d416e1432" content-type="reactionType" xlink:type="simple" xmlns:xlink="http://www.w3.org/1999/xlink"><italic>O</italic>‐acetylation</named-content>, and a subsequent <named-content id="d416e1437" content-type="reactionType" xlink:type="simple" xmlns:xlink="http://www.w3.org/1999/xlink">allylic amination</named-content>. The corresponding novel β<sup>2</sup>‐amino acid derivatives were prepared with excellent <named-content id="d416e1443" content-type="reactionType" xlink:type="simple" xmlns:xlink="http://www.w3.org/1999/xlink">enantioselectivities</named-content> and high yields by <named-content id="d416e1447" content-type="reactionType" xlink:type="simple" xmlns:xlink="http://www.w3.org/1999/xlink">catalytic asymmetric hydrogenation</named-content> using the catalyst rhodium(Et‐Duphos) (Et‐Duphos=2′, 5′, 2′′, 5′′‐tetraethyl‐1, 2‐bis(phospholanyl)benzene)) under mild reaction conditions (up to 99 % <italic>ee</italic> and S/C=1000). The influence of the substrate on the <named-content id="d416e1453" content-type="reactionType" xlink:type="simple" xmlns:xlink="http://www.w3.org/1999/xlink">enantioselectivity</named-content> and reactivity is investigated, and the most suitable substrate configuration for the highly efficient <named-content id="d416e1456" content-type="reactionType" xlink:type="simple" xmlns:xlink="http://www.w3.org/1999/xlink">enantioselective hydrogenation</named-content> of β‐substituted α‐aminomethylacrylates under the Rh–Duphos system is reported. The current protocol provides a very practical, facile, and scalable method for the preparation of heterocyclic and alicyclic β<sup>2</sup>‐amino acids and their derivatives.</p> </abstract>