In the presence of a pyridine N‐oxide, the title reaction affords five‐ and six‐membered α,β‐unsaturated lactones.

The direct ands electivef unctionalization of CÀH bonds offers ap owerful opportunity for greener and shorter routes to valuable chemicals. While still in its infancy,r esearch exploiting the unique features of gold catalysis for the functionalization of aryl CÀHb onds has demonstrated great potentialf or facile regioselective decoration of (hetero)arenes. Particularly within the last five years, am ore gener-al strategy for utilizingo xidative gold catalysis has emanated including an improved understandingo ft he underlying mechanistic pathways. To encourage andfacilitate further research in intermolecularC ÀHf unctionalization of arenes with homogeneous gold catalysis, this Minireview critically presents the transformationsa nd mechanistic data available within this field. Scheme1.Different pathways in gold-catalyzed aryl CÀHf unctionalization. (Nu = nucleophile, R.E. = reductive elimination, E = electrophile, and EAS = electrophilic aromatic substitution).[a] Dr.SørenK ramer obtained his PhD from Aarhus University in 2012 working with homogeneous gold catalysisu nder the supervisiono f Prof. Troels Skrydstrup. His graduate studies included stays at École Polytechnique and University of North Carolina at Chapel Hill. During 2013-2015, Søren conducted post-doctoral research in the field of asymmetric organocatalysis with Prof. Gregory C. Fu at California Institute of Technology.N ow,S øreni s apostdoctoral researcher at Aarhus University with Prof. T. Skrydstrup working with mechanistic elucidation of transition-metal-catalyzed reactions. Scheme2.Oxidative homocoupling of arenesbyT se et al. Scheme3.Oxidative cross-coupling of arenes by Russelle tal. (CSA = camphorsulfonic acid). Scheme4.Mechanistic investigation and proposed reaction mechanism for the aryl-aryl cross-coupling by Russell et al. (TOLS = turnover-limiting step).

Metal-Free Halonium Mediated Acetate Shifts of Ynamides to Access α-HaloAcrylamides/Acrylimides. -The reaction allows access to α-iodo, bromo and chloro acrylamides/acrylimides using the same conditions and halosuccinimides. An α-fluoro analogue (VI) is obtained with low yield using Selectfluor. All reactions proceed with excellent (Z)-selectivity. -(KRAMER, S.; FRIIS, S. D.; XIN, Z.; ODABACHIAN, Y.; SKRYDSTRUP*, T.; Org. Lett. 13 (2011) 7, 1750-1753, http://dx.doi.org/10.1021/ol200269h ; Interdiscip. Nanosci. Cent., Univ. Aarhus, DK-8000 Aarhus, Den.; Eng.) -R. Steudel

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An effective method for the nucleophile‐catalyzed method for the [4 + 1] annulation of sulfonamides with trisubstituted allenes to yield dihydropyrroles with good enantioselectivities is developed.