Synthesis of α-aminonitriles via a FeSO4-mediated oxidative cyanation of tertiary amines with benzoyl cyanide and molecular oxygen or TBHP

Oxidative C-H activation of amines using protuberant lychee-like goethite

“…In spite of burgeoning interest in this area, there are few reports available on this topic 17 , 18 ; Murahashi group utilized molecular oxygen as an oxidant in the presence of ruthenium salt 17 whereas the Fu and co-workers used a catalytic amount of radical initiator (Azobisisobutyronitrile) AIBN 18 . Homogenous vanadium- 19 and iron-based catalysts 20 , 21 were also reported for the same reaction. Recently, a heterogeneous ruthenium-based photocatalyst was used for the synthesis of α-aminonitriles under visible light irradiation 22 .…”

Morpholine As a Scaffold in Medicinal Chemistry: An Update on Synthetic Strategies

“… A metallophotoredox catalysis of C−H functionalization ( A ) and tert‐butyl hydroperoxide radical based couplings toward morpholine functionalization ( B – D ). Reagents and conditions : a) Ni(dtbbpy)Br 2 (5 mol %), TBADT (1 mol %), K 3 PO 4 (1.1 equiv), ACN (0.1 M), 34 W 390 nm Kessil lamp, fan (yield: 48 %); b) TBHP (2 equiv), t ‐BuOK (10 mol %), MeCN, 110 °C, 24 h (yield: 44 %); c) TBHP (1.5 equiv), FeSO 4 ⋅ 7H 2 O (20 mol %), rt, 36 h (yield: 51 %); d) TBHP (10 mol %), Fe(OAc) 2 (10 mol %), DCE, N 2 atm, 80 °C, 3 h (yield: 51 %) . (TBADT: tetrabutylammonium decatungstate)…”

“…An alternative approach to these radical based couplings is utilizing radicals produced through tert‐butyl hydroperoxide (TBHP) (Scheme B−D). TBHP decomposition is mediated by either potassium tert‐butoxide (Scheme B) or an iron catalyst (Scheme C and D) . It should be noted that reactions B and D (Scheme ) require the use of 10 equivalents of the starting morpholine to proceed and the yield is based on the coupling partner, imposing limitations to their broader use.…”

Catalyst‐free straightforward synthesis of 3‐cyano‐3‐arylamino‐2‐oxindoles through hydrocyanation with benzoyl cyanide

“…Benzoyl cyanide is less toxic cyanating agent, which can be easily prepared by reaction of commercial available benzoyl chloride and nontoxic potassium hexacyanoferrate (II) . In recent years, benzoyl cyanide has been reported to act as cyanating agent for terminal alkynes, 3‐arylideneindolin‐2‐ones, naphthalenes, tertiary amines, and aromatic bromides . However, the reports about benzoyl cyanide as a hydrocyanating agent were scarce; only the hydrocyanation of aldehydes was reported …”