Synfacts 2011(8): 0902-0902  
DOI: 10.1055/s-0030-1260835
Organo- and Biocatalysis
© Georg Thieme Verlag Stuttgart ˙ New York

Intermolecular Hydroacylation of Cyclopropenes

Contributor(s): Benjamin List, Steffen Müller
X. Bugaut, F. Liu, F. Glorius*
Westfälische Wilhelms-Universität, Münster, Germany
Further Information

Publication History

Publication Date:
20 July 2011 (online)


Following up on their recently reported intramolecular hydroacylation of electron-neutral olefins (J. Am. Chem. Soc. 2009, 131, 14190), the Glorius group reports an intermolecular version of this reaction. In the presence of the triazolium salt 1 derived NHC, aromatic aldehydes 2 reacted with cyclopropenes 3 to give the desired hydroacylation products 4 in high yields and generally high diastereoselectivities. Mechanistic studies support a scenario in which the Breslow intermediate reacts kinetically favored but reversible with another equivalent of 2 to form the benzoin product. The hydroacylation, which is suggested to be a concerted process, proceeds slower but therefore irreversibly, eventually leading to high yields of the products 4.