The first synchronous programming languages were, AFAIK, Statecharts and Esterel, the former designed by David Harel while he was working alongside Amir Pnueli, who would later win the Turing Award for introducing temporal logic to computer science. https://www.wisdom.weizmann.ac.il/~harel/papers/Statecharts....
Eve also combined synchronous programming with logic programming: https://witheve.com