Six fundamental chemical transformations of aryl carbonyls are achieved by properly adjusting the stoichiometry of the borane-amine and titanium tetrachloride reagent system. This set of reagents acts collectively as a hydride donor, Lewis acid catalyst, and halogen source for the reduction of carbonyls to alcohols, reductive halogenation of carbonyls to halides, deoxygenation of carbonyls to alkanes, dehydroxyhalogenation of alcohols to halides, deoxygenation of alcohols to alkanes, and hydrodehalogenation of halides to alkanes. While the carbonyl reduction is broadly applicable to both aromatic and aliphatic substrates, the remaining reactions are dependent on the stability of the proposed carbocationic intermediates, enabling highly selective reactions at the substrates’ benzylic position. This unique selectivity allows benzylic dehalogenation in the presence of aryl and alkyl halides in addition to highly selective dehydroxyhalogenation of alcohols even for tertiary versus secondary aliphatic and secondary versus primary benzylic substrates using only titanium tetrachloride as the chlorinating agent.

中文翻译：

---

芳基羰基化合物连续、竞争还原、卤化或脱氧中的化学计量依赖性


通过适当调整硼烷-胺和四氯化钛试剂系统的化学计量，实现了芳基羰基的六种基本化学转化。这组试剂共同用作氢化物供体、路易斯酸催化剂和卤素源，用于将羰基还原为醇、羰基还原卤化为卤化物、羰基脱氧为烷烃、醇脱氧为卤化物、醇脱氧为烷烃以及卤化物加氢脱卤为烷烃。虽然羰基还原广泛适用于芳香族和脂肪族底物，但其余反应取决于所提出的碳阳离子中间体的稳定性，从而能够在底物的苄基位置进行高选择性反应。这种独特的选择性允许在芳基和烷基卤化物存在下进行苄基脱卤，此外还可以对醇进行高度选择性的脱羟卤化，即使对于仅使用四氯化钛作为氯化剂的叔级与二级脂肪族和仲级与伯苄基底物也是如此。