Achieving control over higher-order stereogenicity is a long-standing goal in stereoselective catalysis to deliberately address more than a twofold number of stereoisomers per stereogenic unit. Current methods allow control over 2ⁿ stereoisomers and their configurations are routinely assigned using the descriptors (R) and (S) or related binary codes. In contrast, conformational analysis extends beyond this dualistic treatment of stereoisomerism, which constitutes an unmet challenge for catalyst stereocontrol. Here, we report that sixfold stereogenicity is tractable by stereoselective catalysis. By controlling a configurationally stable stereogenic axis with six large rotational barriers, a catalytic [2 + 2 + 2] cyclotrimerization selectively governs the formation of one of six stereoisomers with up to 0:0:2:98:0:0 stereocontrol. Moreover, the stereoselectivity is redirectable by stereodivergent catalysis, providing four of the six stereoisomers as major stereoisomers. The underpinnings of conformational analysis and stereoselective catalysis are thereby conceptually reunited. Novel molecular architectures featuring distinct chemical topologies and unexplored chemical designs are anticipated from catalyst control over higher-order stereogenicity.

实现对高阶立体异构性的控制是立体选择性催化中的一个长期目标，即刻意解决每个立体异构单元中超过两倍数量的立体异构体。当前方法允许控制 2 ⁿ立体异构体，并且它们的配置通常使用描述符 ( R ) 和 ( S) 或相关的二进制代码。相比之下，构象分析超出了立体异构的这种二元处理，这对催化剂立体控制构成了未解决的挑战。在这里，我们报告立体选择性催化可以处理六重立体性。通过控制具有六个大旋转障碍的构型稳定的立体轴，催化 [2 + 2 + 2] 环三聚化选择性地控制六种立体异构体之一的形成，立体控制高达 0:0:2:98:0:0。此外，立体选择性可通过立体发散催化重定向，提供六种立体异构体中的四种作为主要立体异构体。构象分析和立体选择性催化的基础因此在概念上重新统一。