Jeffrey Louis Katz

A tandem acetylene-activated S_NAr-anionic cyclization strategy is presented for the synthesis of chalcogen-containing hetero[5]helicenes. Oxa-, thia-, and selena[5]helicenes are accessed from common ortho-fluoro-ethynylarene precursors, allowing the heteroatoms to be installed at the 1-position or 1- and 12-positions of the hetero[5]helicene inner core surface.

We present poly(meta-phenylene oxides) as versatile and tunable scaffolds for immobilized catalyst design. Their modular synthesis enables the rational incorporation of different side chain groups with positional control along the polymer backbone, providing an easy means to modulate polymer properties, and their corresponding catalytic activity. The coordinative convolution of these polymers with (NH₄)₂PdCl₄ affords efficient, reusable catalysts for various organic transformations.

A classroom activity for learning green chemistry metrics with interlocking building blocks is described. The activity illustrates the strengths and weaknesses of conversion, selectivity, yield, atom economy, reaction mass efficiency, carbon efficiency, E-factor, and effective mass yield by counting, where appropriate, the number of molecular models built, the number of bricks used, or the number of connection points available. The activity is appropriate for students in general chemistry courses through advanced undergraduate green chemistry or industrial chemistry courses.