Circular economy methods of preparing unsaturated compounds

A method of preparing an unsaturated compound, comprising dehydrogenation of a corresponding saturated compound in the presence of a catalyst system under conditions that effect loss of one or more molecules of hydrogen (H2) per molecule of the saturated compound, wherein

• the catalyst system is selected from the group consisting of heterogeneous catalyst systems, homogeneous catalyst systems, and combinations thereof;
• the heterogeneous catalyst system is selected from the group consisting of Pd/C, Pd/alumina, Pd/CG, Pt/C, Pt/alumina, molybdenum oxide, vanadium pentoxide, Rh/alumina, Ru/Al2O3, bismuth molybdate, and combinations thereof;
• the homogeneous catalyst system is selected from soluble transition metal salts, Pincer-based catalysts, and combinations thereof;
• and
• the saturated compound comprises a backbone structure selected from the group consisting of:
• wherein m is an integer from 1 to 20;
• R is hydrogen or oxo (═O), and each open position of said backbone structures is optionally substituted.