Organoalkali Chemistry

Bromine–lithium exchange: An efficient tool in the modular construction of biaryl ligands

“…An effective discrimination between two bromine atoms as a function of their chemical environment has so far been observed only sporadically in such processes [30,34–35 51–52 70–72]. …”

A Concise Atroposelective Formal Synthesis of (–)‐Steganone

“…Column chromatography was carried out using MERCK silica gel (40–63 μm). n ‐Butyllithium (1.6 M in hexanes, Aldrich), was used as solution and its concentration was determined following the Wittig–Harborth Double titration method [(total base) – (residual base after reaction with 1,2‐dibromoethane)] 27 . NMR ‐spectra were recorded with Bruker Avance300 ( 1 H NMR = 300 MHz, 13 C NMR = 75.5 MHz) and Bruker Avance400 ( 1 H NMR: 400 MHz, 13 C NMR: 100.6 MHz) machines.…”

“…Methyl 6‐Iodobenzo[ d ][1,3]dioxole‐5‐carboxylate 27 (14): To a solution of carboxylic acid 13 (2.00 g, 6.85 mmol) in methanol (80 mL), was added dropwise concd. sulfuric acid (5.50 mL, 99.06 mmol) at 25 °C.…”

Sulfone–Metal Exchange and Alkylation of Sulfonylnitriles

“…[1] Formation of metalated nitriles is illustrative of the different metalation strategies used to generate organometallics:traditional base-promoted deprotonation (1!2 or 3;Scheme 1), [2] halogen-metal exchange (5!2 or 3), [3] sulfoxide-metal exchange (6!2 or 3), [4] and sulfide-metal exchange (7!2 or 3). [1] Formation of metalated nitriles is illustrative of the different metalation strategies used to generate organometallics:traditional base-promoted deprotonation (1!2 or 3;Scheme 1), [2] halogen-metal exchange (5!2 or 3), [3] sulfoxide-metal exchange (6!2 or 3), [4] and sulfide-metal exchange (7!2 or 3).…”