I. Introduction 3119 II. Syntheses of Pybox Ligands 3119 III. Pybox−Metal Complexes 3123 A. Syntheses 3123 B. Structures 3125 1. X-ray Crystal Structures 3125 2. Spectroscopic and Computational Results 3128 IV. Reactions 3128 A. Addition to CdO and CdN Double Bonds 3128 1. Aldol Additions and Related Reactions 3128 2. Reductions of Ketones 3133 3. Silylcyanations 3134 4. Other CO and CN Additions 3134 B. Three-Membered Ring Formation from CdC and CdX Double Bonds 3135 1. Cyclopropanation Reactions 3135 2. Aziridination Reactions 3138 3. Epoxidations and Epoxide Ring Opening 3139 C. Other Addition and Substitution Reactions 3140 D. Allylic Oxidations 3140 E. Diels−Alder and Hetero-Diels−Alder Reactions 3141 F. 1,3-Dipolar Cycloaddition Reactions 3144 G. Other Pericyclic Reactions 3146 H. Polymerization and Oligomerization of Alkenes and Alkynes 3147 I. Miscellaneous Reactions 3148 V. The Coordination and the Mechanism of the Chirality Transfer 3150 VI. Conclusion 3152 VII. Acknowledgments 3152 VIII. References 3152

The stereospecific endo dimerization of cyclopentadiene takes place through an asynchronous and symmetrical bispericyclic transition structure, which shows a merging of the 4+2 and 2+4 cycloaddition paths. The shape of the transition structure testifies to the presence of attractive Salem/Houk secondary orbital interactions assisting the endo approach.

In this paper we provide an accurate high-pressure structural and optical study of MAPbI3 hybrid perovskite. Structural data show the presence of a phase transition towards an orthorhombic structure around 0.3 GPa followed by full amorphization of the system above 3 GPa. After releasing pressure the systems keeps the high-pressure orthorhombic phase. The occurrence of these structural transitions is further confirmed by pressure induced variations of the photoluminescence signal at high pressure. These variations clearly indicate that the bandgap value and the electronic structure of MAPI change across the phase transition.3

Peptide-based drugs, despite being relegated as niche pharmaceuticals for years, are now capturing more and more attention from the scientific community. The main problem for these kinds of pharmacological compounds was the low degree of cellular uptake, which relegates the application of peptide-drugs to extracellular targets. In recent years, many new techniques have been developed in order to bypass the intrinsic problem of this kind of pharmaceuticals. One of these features is the use of stapled peptides. Stapled peptides consist of peptide chains that bring an external brace that force the peptide structure into an α-helical one. The cross-link is obtained by the linkage of the side chains of opportune-modified amino acids posed at the right distance inside the peptide chain. In this account, we report the main stapling methodologies currently employed or under development and the synthetic pathways involved in the amino acid modifications. Moreover, we report the results of two comparative studies upon different kinds of stapled-peptides, evaluating the properties given from each typology of staple to the target peptide and discussing the best choices for the use of this feature in peptide-drug synthesis.

Highlights d Analysis of TRAP1 dynamics allows discovery of paralogselective allosteric inhibitors d Small molecules targeting TRAP1 revert TRAP1-dependent succinate dehydrogenase inhibition d Allosteric TRAP1 inhibitors abolish tumorigenic growth of neoplastic cells d Selective targeting of TRAP1 activity provides new antagonists of chaperones