... In addition to being versatile intermediates and building blocks for chemical synthesis, alkenyl bromides and chlorides are also commonly found in natural products. ... 4, 1,10-phenanthroline, 40, 55. 5, 2,2′-bipyridine, 40, 48. ... 9, trans-N,N′-dimethylcyclohexane-1,2-diamine, 0, 76. ...