The divalent carbene carbon centre in cyclic (alkyl)(amino)carbenes (CAACs) is known to exhibit transition-metal-like insertion into E–H σ-bonds (E = H, N, Si, B, P, C, O) with formation of new, strong C–E and C–H bonds. Although subsequent transformations of the products represent an attractive strategy for metal-free synthesis, few examples have been reported. Herein we describe the dehydrogenation of phosphine-boranes, RR’PH·BH₃, using a CAAC, which behaves as a stoichiometric hydrogen acceptor to release monomeric phosphinoboranes, [RR’PBH₂], under mild conditions. The latter species are transient intermediates that either polymerise to the corresponding polyphosphinoboranes, [RR’PBH₂]_n (R = Ph; R’ = H, Ph or Et), or are trapped in the form of CAAC-phosphinoborane adducts, CAAC·H₂BPRR’ (R = R’ = tBu; R = R’ = Mes). In contrast to previously established methods such as transition metal-catalysed dehydrocoupling, which only yield P-monosubstituted polymers, [RHPBH₂]_n, the CAAC-mediated route also provides access to P-disubstituted polymers, [RR’PBH₂]_n (R = Ph; R’ = Ph or Et).

已知环状（烷基）（氨基）卡宾（CAAC）中的二价卡宾碳中心表现出类似过渡金属的插入 E-H σ 键（E = H、N、Si、B、P、C、O ) 形成新的、牢固的 C-E 和 C-H 键。尽管产物的后续转化代表了无金属合成的有吸引力的策略，但报道的例子很少。在此，我们描述了使用CAAC对膦硼烷RR'PH·BH _{3进行脱氢，CAAC充当化学计量氢受体，在温和条件下释放单体膦硼烷[RR'PBH 2} ]。后者是瞬时中间体，可以聚合成相应的聚膦硼烷 [RR'PBH ₂ ] _n（R = Ph；R' = H、Ph 或 Et），或者以 CAAC-膦硼烷加合物 CAAC· 的形式捕获H ₂ BPRR'（R = R' =  t Bu；R = R' = Mes）。与先前建立的方法（例如过渡金属催化脱氢偶联）相比，该方法仅产生 P-单取代聚合物 [RHPBH ₂ ] _n，CAAC 介导的途径还提供了获得 P-二取代聚合物 [RR'PBH ₂ ] _n的途径（ R = Ph；R' = Ph 或 Et)。