The generation of molecular complexity is a primary goal in the field of synthetic chemistry. In the context of retrosynthetic analysis, the concept of molecular complexity is central to identifying productive disconnections and the development of efficient total syntheses. However, this field-defining concept is frequently invoked on an intuitive basis without precise definition or appreciation of its subtleties. Methods for quantifying molecular complexity could prove useful for characterizing the state of synthesis in a more rigorous, reliable and reproducible fashion. As a first step to evaluating the importance of these methods to the state of the field, here we present our perspective on the development of molecular complexity quantification and its implications for chemical synthesis. The extension and application of these methods beyond computer-aided synthesis planning and medicinal chemistry to the traditional practice of ‘complex molecule’ synthesis could have the potential to unearth new opportunities and more efficient approaches for synthesis.

分子复杂性的产生是合成化学领域的一个主要目标。在逆合成分析的背景下，分子复杂性的概念对于识别生产性断开和开发有效的全合成至关重要。然而，这个定义场的概念经常被直觉地援引，而没有精确的定义或对其微妙之处的理解。量化分子复杂性的方法可能有助于以更严格、可靠和可重复的方式表征合成状态。作为评估这些方法对该领域状态的重要性的第一步，我们在这里提出了我们对分子复杂性量化发展及其对化学合成的影响的看法。这些方法从计算机辅助合成计划和药物化学扩展到传统的“复杂分子”合成实践中，有可能为合成发现新的机会和更有效的方法。