α-Azido ketones, Part 6. Reduction of acyclic and cyclic α-azido ketones into α-amino ketones: old problems and new solutions

Abstract

Comparative experiments on the selective reduction of α-azido ketones to α-amino ketones revealed that tin(II) chloride reduction followed by immediate protection with Boc group is the method of choice. This methodology proved to be useful for more complex substrates, too. Chromium(II) acetate also resulted in the desired products but in lower yields due to a competitive deazidation procedure. A mechanism to explain this deazidation was suggested.

Identification of Potent and Selective Hydantoin Inhibitors of Aggrecanase-1 and Aggrecanase-2 That Are Efficacious in Both Chemical and Surgical Models of Osteoarthritis

“…Prepared from PhMgBr (5.15 g, 96%) as a clear colorless oil using the general procedure. Analytical data were consistent with previously published data …”

“…Analytical data were consistent with previously published data. 25 tert-Butyl N-[2-(3-Methyl-2-pyridyl)-2-oxo-ethyl]carbamate (3b). 2-Bromo-3-methylpyridine (10 mL, 89.64 mmol) was dissolved in dry tetrahydrofuran (50 mL) and cooled to −10 °C under nitrogen.…”

Synthesis and Consecutive Reactions of α-Azido Ketones: A Review

“…The reduction of α-azido ketones to α-amino ketones using tin (II) chloride followed by Boc group protection was reported by Patonay in 2009 [50]. Cr (II) was also used as catalyst for this reduction, but the products were formed in low yields (Scheme 78).…”

Preparation of Phenacyl Azides and Their Application Advances in Organic Synthesis

“…为了进一步提高 Hӧrmann [43] 的报道, 使用钯/碳试剂可以催化氢化苯乙 酰叠氮, 继续用 HCl 乙醚溶液处理, 这样 α-氨基苯乙酮 的盐酸盐以沉淀的形式析出(Scheme 6). 为了找到更简 便的方法将苯乙酰叠氮转化为 α-氨基苯乙酮, Patonay 等 [44] 1983 年, Knittel [45] 利用醋酸哌啶盐催化芳乙酰叠氮 先脱氮生成 α-亚氨基芳基乙酮, 再与对亚硝基二甲基苯 胺进行脱氢氧化反应, 得到芳甲酰腈(Scheme 7). 如果 反应时间过长, 芳甲酰腈还会继续与哌啶发生加成反 应, 最终转化成 α-亚氨基-α-哌啶基芳基乙酮.…”