KOtBu as a Single Electron Donor? Revisiting the Halogenation of Alkanes with CBr4 and CCl4

Abstract

The search for reactions where KOtBu and other tert-alkoxides might behave as single electron donors led us to explore their reactions with tetrahalomethanes, CX4, in the presence of adamantane. We recently reported the halogenation of adamantane under these conditions. These reactions appeared to mirror the analogous known reaction of NaOH with CBr4 under phase-transfer conditions, where initiation features single electron transfer from a hydroxide ion to CBr4. We now report evidence from experimental and computational studies that KOtBu and other alkoxide reagents do not go through an analogous electron transfer. Rather, the alkoxides form hypohalites upon reacting with CBr4 or CCl4, and homolytic decomposition of appropriate hypohalites initiates the halogenation of adamantane.

One‐Carbon Ring Expansion of Indoles and Pyrroles: A Straightforward Access to 3‐Fluorinated Quinolines and Pyridines

“…At present, the mechanism for the generation of bromofluorocarbene from CFBr 3 is not well understood. One proposed pathway suggests that CFBr 3 reacts with LiO t Bu to produce hypobromite t BuOBr and CFBr 2 − anion [13] . This CFBr 2 − species then undergoes decomposition to yield bromofluorocarbene.…”

“…Indoles with 2-position substituents underwent efficient ring expansion to afford polysubstituted fluoroquinolines that are otherwise difficult to obtain. [14] Skeletal editing of indoles bearing electron-neutral (3,4,8,11,13) or electron-donating (7, 12, 15) substituents at the 3-, 4-, 5-, 6-, or 7-position furnished their corresponding 3-fluorinated quinolines in moderate to good yields. Electron-deficient indoles (5, 10) proceeded smoothly, although increased loading of LiO t Bu and dibromofluoromethane (2) were crucial for a high conversion of the indoles.…”

“…One proposed pathway suggests that CFBr 3 reacts with LiO t Bu to produce hypobromite t BuOBr and CFBr 2 À anion. [13] This CFBr 2 À species then undergoes decomposition to yield bromofluorocarbene. In addition, this reaction is sensitive to base identity.…”

A comparison between steepest descent and non-linear conjugate gradient algorithms for binding energy minimization of organic molecules

“…In this, the first column is the standard symbol of that atom and the next three columns are the x, y, and z-coordinate of the atom in 3D space, which has been obtained from experiments and x-ray diffraction. By using these .xyz files we are calculating the necessary values for computing binding energy which are Bond length, Bond angle, and Torsional angle [19].…”

Direct Trideuteromethylation of Sulfenate Anions Generated In Situ from β-Sulfinyl Esters: An Access to Trideuteromethyl Sulfoxides

“…It was documented in the literature that tert -butoxide ions could promote reactions through a radical pathway . Therefore, we aimed to conduct a control experiment in the presence of a radical scavenger to comprehend the reaction mechanism.…”