Organic synthesis plays an important role in modern industrial products, such as development of medicines, agrochemicals, functional additives to polymers and other products, and thus affects a wide range of daily consumer choices and activities. As a classical chemistry research topic, organic synthesis remains a dynamic field, because of many sophisticated challenges waiting to be resolved. In general, research process in developing new syntheses can be split in two parts: synthesis planning and validating plans in wet lab. Thanks to the developments in high-throughput experimentation techniques, robotics and lab automation, the validation part could be accelerated as demonstrated by several research groups based in both academia and industry. For synthesis planning, significant progress had also been made by taking advantages of digitalising chemical data and having access to significant computing resources. The concept of computer-aided synthesis planning (CASP) has attracted significant interest over the past few decades.