A novel strategy employing cyclohexyl spectator ligands in Stille cross-coupling reactions has been developed as a general solution to the long-standing challenge of conducting stereospecific cross-coupling reactions at nitrogen-containing stereocenters. This method enables direct access to enantioenriched products that are difficult (or impossible) to obtain via alternative preparative methods. Selective and predictable transfer of a single secondary alkyl unit can be achieved under reaction conditions that exploit subtle electronic differences between activated and unactivated alkyl units. Through this approach, enantioenriched α-stannylated nitrogen-containing stereocenters undergo Pd-catalyzed arylation and acylation reactions with exceptionally high stereofidelity in all instances investigated. We demonstrate this process by using α-stannylated pyrrolidine, azetidine, and open-chain (benzylic and non-benzylic) nucleophiles in stereospecific reactions. This process will facilitate rapid and reliable access to enantioenriched compounds possessing nitrogen-substituted stereocenters, which constitute ubiquitous structural motifs in biologically active compounds emerging from the drug-discovery process.

作为在含氮立体中心进行立体定向交叉偶联反应的长期挑战的常规解决方案，已开发出在Stille交叉偶联反应中采用环己基旁观者配体的新策略。该方法使得能够直接获得难以（或不可能）通过替代制备方法获得的对映体富集的产品。在利用活化的和未活化的烷基单元之间的细微电子差异的反应条件下，可以实现单个仲烷基单元的选择性和可预测的转移。通过这种方法，在所有研究的实例中，对映体富集的α-甲锡烷基化的含氮立体中心都经历了Pd催化的芳构化和酰化反应，并具有极高的立体保真度。我们通过立体定向反应中使用α-苯乙烯基吡咯烷，氮杂环丁烷和开链（苄基和非苄基）亲核试剂来证明这一过程。该过程将有助于快速可靠地获得具有氮取代的立体中心的对映体富集的化合物，该化合物在从药物发现过程中出现的生物活性化合物中构成普遍存在的结构基序。