The first ruthenium-catalyzed oxidative homo- and cross-coupling of exclusive vinyl derivatives giving highly valued 1,3-diene building blocks is reported. The catalytic system is based on readily available reagents and it...

The present review describes the most relevant advances dealing with supramolecular catalysis in which metalloporphyrins are employed as substrate-recognition sites in the second coordination sphere of the catalyst. The kinetically-labile interaction between metalloporphyrins (typically, those derived from zinc) and nitrogen- or oxygen-containing substrates is energetically comparable to those non-covalent interactions (i.e. hydrogen bonding) found in enzymes enabling substrate-preorganization. Much inspired from this host-guest phenomena, the catalytic systems described in this account display unique activities, selectivities and action modes difficult to reach applying purely covalent strategies.

Transition metal catalysis benefitting from supramolecular interactions in the secondary coordination sphere in order to pre-organize substrates around the active site and reach a specific selectivity typically occur under long...

The periodic table of chemistry contains all synthetic and naturally occurring elements. The elements are arranged in seven horizontal periods from left to right with increasing atomic number. The periodic table is divided into two groups: metals and nonmetals, within elements moving from left to right, the elements get less metallic, culminating in nonmetals on the far right side of the table. Further, the elements are also arranged in eight vertical columns or groups for those with similar physical and chemical properties. A model equation has been developed based on the 8-group and the 7-periods from which trends of elements has been calculated. Among the trends in the periodic table that were calculated are ionization energy, atomic size and effective nuclear charge. It has been discovered that the calculated theoretical values from the model equation rhyme well with the actual values for each element with few exceptions.