Studying competitive lithiations at alpha-, ortho-, and benzylic positions in various N-protected aniline derivatives
作者:Martin Schmid、Birgit Waldner、Michael Schnürch、Marko D. Mihovilovic、Peter Stanetty
DOI:10.1016/j.tet.2011.02.056
日期:2011.4
The directing effects of the t-BuOCONH– (NHBoc) and the t-BuCONH– (NH–pivaloyl) groups have been investigated on a series of differently substituted anilines. Depending on the nature of the directing group and the substrate, lithiation either occurred in the ortho-, benzylic-, or alpha-position. In general, it was observed that ortho-lithiation is the least facile process and alpha-lithiation slightly
Chiral ligands: Hg(OTf)2‐catalyzed cyclization of anilinosulfonamideallylalcohol is described; this reaction gives 2‐vinyl indoline derivatives in good yields and excellent enantioselectivity by using a chiral BINAPHANE ligand (see scheme).
Stereodivergent Synthesis of Two Novel α-Aminophosphonic Acids Characterised by a cis-Fused Octahydroindole System
作者:Alicia Arizpe、Francisco J. Sayago、Ana I. Jiménez、Mario Ordóñez、Carlos Cativiela
DOI:10.1002/ejoc.201100229
日期:2011.6
The synthesis of two new α-aminophosphonic acids, namely (2S*,3aS*,7aS*)- and (2R*,3aS*,7aS*)-octahydroindole-2-phosphonic acids, is described. They are analogues of phosphoproline with a cyclohexane ring fused to the pyrrolidine moiety. The ring junction has cisstereochemistry in both cases, but the two compounds differ in the relative orientation of the cyclohexane and phosphonate moieties. The
A practical approach to α-aminophosphonates has been developed through an In(OTf)3-catalyzed N-α phosphonylation of N,O-acetals with triethylphosphite 7. Indoline and isoindoline N,O-acetals 6a–6j and 9a–9j and chain N,O-acetals 11a–11p were subjected to a Lewis acid catalyzed N-α phosphonylation process. As a result, the desired α-aminophosphonates 8a–8j, 10a–10j and 12a–12p were obtained in moderate