Oxidation of Active Hydrogen Compounds with 2-Chlorotetramethylguanidine

Transformation of Carbohydrate Derived 4‐Azidopentanals Into Highly Functionalized Pyrrolidines Via a Tandem Staudinger/aza‐Wittig/Ugi Multicomponent Reaction

“…We are currently in the process of investigating the use of these compounds in both directions. H NMR spectra or a deuterated solvent for 13 C NMR spectra. Coupling constants (J) are given in Hertz.…”

“…Where indicated, NMR peak assignments were made using COSY, NOESY (t mix ¼ 1 s), and HMQC experiments. All presented 13 C-APT spectra are proton decoupled. Optical rotations were measured on a Propol automatic polarimeter (sodium D-line, l ¼ 589 nm).…”

“…To a dry solution of 14 (0.74 g, 1.00 mmol) in DMF (6 mL) was added tetramethylguanidinium azide (TMGA) [13] (1.6 g, 10 mmol) and the mixture was stirred for 24 h at 90 8C. …”

Complexes of Manganese, Iron, Zinc, and Molybdenum with a Superbasic Tris(guanidine) Derivative of Tris(2-ethylamino)amine (Tren) as a Tripod Ligand

“…It is also observed for the hexamethylguanidinium cation. [21] In order to avoid steric interactions, the Me 2 N substituents adopt a mutually twisted propeller-like conformation [21,22] rather than a coplanar one. The UV/Vis spectrum of 1 in MeCN shows an absorption at 216 nm with a molar extinction coefficient ε of approximately 1·10 4 for each guanidinium unit, attributable to the πǞπ* transition of the CϭN bond.…”

Regio- and stereoselective behavior of l-arabinal-derived vinyl epoxide in nucleophilic addition reactions. Comparison with conformationally restricted d-galactal-derived analogs

“…The reaction of epoxide 2 with n-propylamine (as the solvent/ nucleophile, protocol A) and tetramethylguanidine azide (TMGA in MeCN, protocol B) 14 was not useful to our aim because only the corresponding anti-1,2-addition product, the trans amino alcohol 23 and trans azido alcohol 24, respectively, were obtained in a completely 1,2-regio-and anti-stereoselective fashion, in accordance with the corresponding results previously obtained with epoxides 1b and 1b-Me (Scheme 11). 1a,d,15 Decidedly different is the behavior of epoxide 2 with a further source of azide, TMSN 3 in MeCN (protocol B).…”