Organocerium additions to proline-derived hydrazones: synthesis of enantiomerically enriched amines
作者:Scott E. Denmark、James P. Edwards、Theodor Weber、David W. Piotrowski
DOI:10.1016/j.tetasy.2010.04.042
日期:2010.5
The addition of organocerium reagents (from both organolithium and organomagnesium precursors) to chiral aldehyde hydrazones prepared from 1-aminoproline derivatives has been studied. The additions proceed in good yield and high diastereoselectivity and with good nucleophile (Me, n-Bu, i-Pr, t-Bu, Ph, etc.) and substrate scope (alkyl, alkenyl and aryl). The resulting hydrazines can be converted to
Total synthesis of (±) mutisianthol and (±) epi-mutisianthol via intramolecular oxidative Heck cyclization approach
作者:Shashikant B. Bhorkade、Kishor B. Gavhane、Vaishali S. Shinde
DOI:10.1016/j.tet.2016.02.057
日期:2016.4
A simple and straight forward synthesis of (±) mutisianthol and its epimer is described. Implementation of 4-pentenal derivative for palladium catalyzed intramolecular 5-endo-trig Heck cyclization is effective. Other key steps involved are Wittig olefination with allyloxymethylenetriphenylphosphorane, [3,3] sigmatropic rearrangement and chemoselective reduction of double bond.
ATP3 and MTP3: Easily Prepared Stable Perruthenate Salts for Oxidation Applications in Synthesis
作者:Peter W. Moore、Christopher D. G. Read、Paul V. Bernhardt、Craig M. Williams
DOI:10.1002/chem.201800531
日期:2018.3.26
commercial catalyst supply. However, the mild instability of TPAP creates preparation, storage, and reaction reproducibility issues, due to unpreventable slow decomposition. In search of attributes conducive to catalyst longevity an extensive range of novelperruthenate salts were prepared. Subsequent evaluation unearthed a set of readily synthesized, bench stable, phosphonium perruthenates (ATP3 and
We describe the characterisation of the O-methyltransferase JerF from the late stages of jerangolid biosynthesis. JerF is the first known example of an enzyme that catalyses the formation of a non-aromatic, cyclic methylenolether. The enzyme was overexpressed in E. coli and the cell-free extracts were used in bioconversion experiments. Chemical synthesis gave access to a series of substrate surrogates
A Systematic Study of Functionalized Oxiranes as Initiating Groups for Cationic Polycyclization Reactions
作者:Goreti Rajendar、E. J. Corey
DOI:10.1021/jacs.5b03229
日期:2015.5.6
Three different methods have been developed that effectively utilize chiral oxiranes derived from Katsuki-Sharpless epoxidation of allylic alcohols as initiating groups for cationic cyclization of unsaturated substrates to form chiral polycycles. This type of transformation has previously been problematic. These employ either epoxy-methoximes, vinyl-substituted oxiranes, or hydroxymethyl oxiranes.