Aza-Baylis–Hillman reaction

<h2 id="asymmetric-aza-bh">Asymmetric aza-BH</h2>
<p>Aza-BH reactions are known in <a href="/facts/Asymmetric_synthesis/5hJe37TL">asymmetric synthesis</a> by making use of <a href="/facts/Chiral_ligand/yeaTGaRC">chiral ligands</a>. In one study,<a class="footnote-ref" id="fnref:4" href="#fn:4"><sup>4</sup></a> for the first time, successful use was made of a chiral solvent based on an <a href="/facts/Ionic_liquid/Ypse8taj">ionic liquid</a> (IL). 
</p>

<p>This solvent is a condensation product of L-(−)-<a href="/facts/Malic_acid/mSbExe77">malic acid</a> (available from the <a href="/facts/Chiral_pool/tca02GnW">chiral pool</a>), <a href="/facts/Boric_acid/0so68XIK">boric acid</a> catalyzed by <a href="/facts/Sodium_hydroxide/xjtdYtq7">sodium hydroxide</a>. When the sodium counter ion is replaced by a bulky <a href="/facts/Ammonium_salt/jYm8wc1n">ammonium salt</a> the resulting ionic liquid has a <a href="/facts/Melting_point/MY0w0h0k">melting point</a> of −32°C.
</p>

<p>This IL serves as the chiral solvent for the aza-BH reaction between <i>N-(4-bromobenzylidene)-4-toluenesulfonamide</i> and <a href="/facts/Methyl_vinyl_ketone/wData1cm">methyl vinyl ketone</a> catalyzed by <a href="/facts/Triphenylphosphine/nYFNCVcJ">triphenylphosphine</a> with <a href="/facts/Chemical_yield/fkBhd9dH">chemical yield</a> 34–39% and <a href="/facts/Enantiomeric_excess/TJlYl4gn">enantiomeric excess</a> 71–84%.
</p>

<h2 id="external-links">External links</h2>
<ul><li><a href="https://www.organic-chemistry.org/Highlights/2006/30JanuaryA.shtm">https://www.organic-chemistry.org/Highlights/2006/30JanuaryA.shtm</a></li></ul>

<h2 id="references">References</h2>

<ol>
<li id="fn:1"><p>Declerck, Valérie; Martinez, Jean; Lamaty, Frédéric (2009). "aza-Baylis−Hillman Reaction". Chemical Reviews. 109 (1): 1–48. doi:10.1021/cr068057c. PMID 19140772. <a href="/wiki/Chemical_Reviews" target="_blank">/wiki/Chemical_Reviews</a> <a href="#fnref:1" class="footnote-back-ref">↩</a></p></li>
<li id="fn:2"><p>Bifunctional Organocatalysts for Enantioselective aza-Morita–Baylis–Hillman Reaction Katsuya Matsui, Shinobu Takizawa, and Hiroaki Sasai J. Am. Chem. Soc.; 2005; 127(11) pp 3680 - 3681; (Communication) doi:10.1021/ja0500254 Abstract[permanent dead link‍] <a href="/wiki/J._Am._Chem._Soc." target="_blank">/wiki/J._Am._Chem._Soc.</a> <a href="#fnref:2" class="footnote-back-ref">↩</a></p></li>
<li id="fn:3"><p>Bifunctional Activation and Racemization in the Catalytic Asymmetric Aza-Baylis–Hillman Reaction Pascal Buskens, Jürgen Klankermayer, and Walter Leitner J. Am. Chem. Soc.; 2005; 127(48) pp 16762 - 16763; (Communication) doi:10.1021/ja0550024 Abstract[permanent dead link‍] <a href="/wiki/J._Am._Chem._Soc." target="_blank">/wiki/J._Am._Chem._Soc.</a> <a href="#fnref:3" class="footnote-back-ref">↩</a></p></li>
<li id="fn:4"><p>Gausepohl, Rolf; Buskens, Pascal; Kleinen, Jochen; Bruckmann, Angelika; Lehmann, Christian W.; Klankermayer, Jürgen; Leitner, Walter (2006). "Highly Enantioselective Aza-Baylis–Hillman Reaction in a Chiral Reaction Medium". Angewandte Chemie International Edition. 45 (22): 3689–3692. doi:10.1002/anie.200600327. PMID 16708413. <a href="/wiki/Angewandte_Chemie_International_Edition" target="_blank">/wiki/Angewandte_Chemie_International_Edition</a> <a href="#fnref:4" class="footnote-back-ref">↩</a></p></li>
</ol>

Aza-Baylis–Hillman reaction open-in-new

Aza-Baylis–Hillman reaction