We demonstrate a greener borrowing hydrogen methodology using the π-benzylpalladium system, which offers an efficient and environmentally friendly dehydrative N-monobenzylation of 2-aminopyridines with benzylic alcohols in the absence of base. The crossover experiment using benzyl-α,α-d₂ alcohol and 3-methylbenzyl alcohol afforded H/D scrambled products, suggesting that the dehydrative N-benzylation in our catalytic system involves a borrowing hydrogen pathway. KIE experiments show that C–H bond cleavage at the benzylic position of benzyl alcohol is involved in the rate-determining step (KIE = 2.9). This simple base-free protocol can be achieved under mild conditions in an atom-economic process, affording the desired products in moderate to excellent yields.

中文翻译：

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借用氢方法：水中2-氨基吡啶的钯催化脱水N-苄基化

我们证明了使用π-苄基钯体系的更绿色的借用氢方法，该方法可在不存在碱的情况下，用苄基醇对2-氨基吡啶进行高效，环保的N-单苄基脱水。使用苄基-α交叉的实验中，α- d ₂醇和3-甲基苄基，得到H / d醇加扰的产品，这表明脱水Ñ在我们的催化系统中，苄基化涉及一个借用的氢途径。KIE实验表明，速率测定步骤涉及苯甲醇的苄基位置的C–H键断裂（KIE = 2.9）。这种简单的无碱方案可以在温和的条件下以原子经济的方法实现，以中等至极好的收率提供所需的产物。