Who are the pioneers of synthetic biology, and what contribution did they make?

Francois Jacob and Jacques Monod are two of the pioneers of synthetic biology. 

They found the existence of regulatory circuits that underpin the response of a cell to its environment in 1961 and promoted the first synthetic biology publication that enabled scientists to assemble new regulatory systems from molecular components.

Reference

Monod, Jacques, and François Jacob. "General conclusions: teleonomic mechanisms in cellular metabolism, growth, and differentiation." Cold Spring Harbor symposia on quantitative biology. Vol. 26. Cold Spring Harbor Laboratory Press, 1961.