Media type: E-Article Title: Facial Diastereoselectivity in Cationic Propargylations with Planar‐Chiral AreneCr(CO)3‐Substituted Propargyl Cations Contributor: Netz, Astrid; Polborn, Kurt; Nöth, Heinrich; Müller, Thomas J. J. imprint: Wiley, 2005 Published in: European Journal of Organic Chemistry Language: English DOI: 10.1002/ejoc.200400798 ISSN: 1434-193X; 1099-0690 Keywords: Organic Chemistry ; Physical and Theoretical Chemistry Origination: Footnote: Description: <jats:title>Abstract</jats:title><jats:p>The planar‐chiral (<jats:italic>o</jats:italic>‐methoxyphenyl)chromium tricarbonyl‐substituted propargyl cation <jats:bold>4</jats:bold> reacts with silyl enol ether derivatives <jats:bold>5</jats:bold> with poor and with enamines <jats:bold>6</jats:bold> with good facial diastereoselectivity to give rise to the (arene)carbonylchromium‐substituted propargylated cyclohexan‐2‐ones <jats:bold>7 </jats:bold>and<jats:bold> 8</jats:bold>, carboxylic acid <jats:bold>9</jats:bold>, γ‐lactone <jats:bold>10</jats:bold>, cyclopentan‐2‐one <jats:bold>11</jats:bold>, and esters <jats:bold>16</jats:bold> and <jats:bold>17</jats:bold>. Structural correlations were unambiguously deduced from X‐ray structure analyses of <jats:bold>7a</jats:bold>, <jats:bold>9a</jats:bold>, and <jats:bold>17a</jats:bold>. The origin of facial diastereoselectivity with this class of organometallic electrophiles lies in steric and stereoelectronic biases rather than in purely electronic nucleophilicity. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)</jats:p>