Intermolecular addition of photochemically generated N-centered aminium and amidyl radicals 13a-d and 16a,b, respectively, to the cyclic alkyne 1 initiates a radical translocation/cyclization cascade, followed by an oxidative termination step that eventually leads to formation of the bicyclic ketones 7a and 8a. Computational studies were performed to gain insight into the mechanism of these reactions, which are an interesting modification of the recently discovered concept of self-terminating radical cyclizations.

Addition of various organic O‐centered radicals XO• {i.e. (alkoxycarbonyl)oxyl radicals, ROC(O)O•, [(alkoxycarbonyl)acyl]oxyl radicals, ROC(O)C(O)O•, (carbamoyl)oxyl radicals, R2NC(O)O•, alkoxyl radicals, RO•, and nitroxyl radicals, R2NO•} to alkynes initiates an oxidative radical cyclization cascade, which is terminated by release of a C‐ or N‐centered radical X•. This finding clearly highlights the generality of the recently discovered concept of self‐terminating radical oxygenations, through which C≡C triple bonds may be converted into carbonyl groups under very mild reaction conditions. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)

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The bifunctional metalloligand bis(carboxyethylgermanium)sesquioxide, (HOOCCH 2 CH 2 Ge) 2 O 3 , was employed in the systematic high-throughput (HT) investigation of the system Zn 2+ / (HOOCCH 2 CH 2 Ge) 2 O 3 /H 2 O/C 4 H 9 OH. Two new metal-organogermanates Zn[(OOCCH 2 CH 2 Ge) 2 O 3 ] (1) and Zn 2 (O 3 GeCH 2 CH 2 COO) (2) were discovered that show two new structural motifs for this class of * Prof. Dr. N. Stock