138212-44-9Relevant articles and documents
Palladium(II)-catalyzed oxidative cyclization of allylic tosylcarbamates: Scope, derivatization, and mechanistic aspects
Joosten, Antoine,Persson, Andreas K. ?.,Millet, Renaud,Johnson, Magnus T.,B?ckvall, Jan-E.
supporting information, p. 15151 - 15157 (2013/01/15)
A highly selective oxidative palladium(II)-catalyzed (Wacker-type) cyclization of readily available allylic tosylcarbamates is reported. This operationally simple catalytic reaction furnishes tosyl-protected vinyl-oxazolidinones, common precursors to syn-1,2-amino alcohols, in high yield and excellent diasteroselectivity (>20:1). It is demonstrated that both stoichiometric amounts of benzoquinone (BQ) as well as aerobic reoxidation (molecular oxygen) is suitable for this transformation. The title reaction is shown to proceed through overall trans-amidopalladation of the olefin followed by β-hydride elimination. This process is scalable and the products are suitable for a range of subsequent transformations such as: kinetic resolution (KR) and oxidative Heck-, Wacker-, and metathesis reactions.
Silver(I)-catalyzed aminocyclization of 2,3-butadienyl and 3,4-pentadienyl carbamates: An efficient and stereoselective synthesis of 4-vinyl-2-oxazolidinones and 4-vinyltetrahydro-2H-1,3-oxazin-2-ones
Kimura,Tanaka,Tamaru
, p. 1689 - 1705 (2007/10/02)
Silver(I) salts in combination with an appropriate base (mostly triethylamine) catalyzed the aminocyclization of N-substituted 2,3-butadienyl carbamates 1 (benzene, 50°C) to provide 4-vinyl-2-oxazolidinones 2 in good yields. The stereoselectivity (trans-2/cis-2) ranged from 1.4 for C5-Me to >30 for C5-phenyl, isopropenyl, and t-butyl derivatives. 3,4-Pentadienyl tosylcarbamates 3, the one-carbon higher homologues of 1, underwent a similar cyclization to give 4-vinyltetrahydro-2H-1,3-oxazin-2-one 4 in synthetically useful yields and in higher trans selectivities than 1.