Direct measurement of three different deformations near the ground state in an atomic nucleus.

Atomic nuclei serve as prime laboratories for investigations of complex quantum phenomena, where minor nucleon rearrangements cause significant structural changes. Pb is the heaviest known neutron-deficient Pb isotope that can exhibit three distinct shapes: prolate, oblate, and spherical, with nearly degenerate excitation energies. Here we report on the combined results from three state-of-the-art measurements to directly observe these deformations in Pb.

Atom Efficient Synthesis of Selectively Difluorinated Carbocycles through a Gold(I)-Catalyzed Cyclization.

The intramolecular carbocyclization of difluorinated enol acetals has been achieved for the first time using gold(I) catalysis. Difluorinated enol acetals bearing a pendant alkene group can be cyclized and reduced in one pot to form fluorinated diol motifs. Alternatively, the cyclization of terminal alkynes allows for the synthesis of fluorinated pyran scaffolds.

Developing the Saegusa-Ito Cyclisation for the Synthesis of Difluorinated Cyclohexenones.

Palladium(II)-catalysed cycloalkenylation (Saegusa-Ito cyclisation) has been used for the first time to transform difluorinated silylenol ethers to difluorinated cycloalkenones under mild conditions. The silylenol ether precursors were prepared in two high-yielding steps from trifluoroethanol, and cyclised in moderate to good yields. A combination of air and copper(I) chloride in acetonitrile gave the turnover of the initial palladium(II) salt, whereas the provision of an oxygen atmosphere ensured more rapid reaction.

Suzuki-Miyaura coupling reactions of iodo(difluoroenol) derivatives, fluorinated building blocks accessible at near-ambient temperatures.

A recently developed method for the near-ambient generation of difluorovinylzinc reagents has facilitated the preparation of 1-(N,N-diethylcarbamoyloxy)-2,2-difluoro-1-iodoethene and 2,2-difluoro-1-iodo-1-(2'-methoxyethoxymethoxy)ethene. The utility of these reagents has been investigated in Suzuki-Miyaura couplings with a range of potassium trifluoroborate coupling partners, with the scope of successful couplings proving wide. Deiodinated species appeared as significant side products, but a solvent change from i-PrOH to t-BuOH suppressed the pathway to these species and improved coupling yields.