Tandem Palladium and Isothiourea Relay Catalysis: Enantioselective Synthesis of α-Amino Acid Derivatives via Allylic Amination and [2,3]-Sigmatropic Rearrangement
作者:Stéphanie S. M. Spoehrle、Thomas H. West、James E. Taylor、Alexandra M. Z. Slawin、Andrew D. Smith
DOI:10.1021/jacs.7b05619
日期:2017.8.30
has been developed for the enantioselective synthesis of α-aminoacid derivatives containing two stereogenic centers from readily accessible N,N-disubstituted glycine aryl esters and allylic phosphates. The optimized process uses a bench-stable succinimide-based Pd precatalyst (FurCat) to promote Pd-catalyzed allylic ammonium salt generation from the allylic phosphate and the glycine aryl ester. Subsequent
A cobalt-catalyzed highly (Z)-selective semihydrogenation of alkynes using molecular H2 was developed using commercially available and cheap cobalt precursors. A variety of (Z)-alkenes were obtained in moderate to excellent selectivities...
Base catalysed rearrangements involving ylide intermediates. Part 1. The rearrangements of diallyl- and allylpropynyl-ammonium cations
作者:Robert W. Jemison、Trevor Laird、W. David Ollis、Ian O. Sutherland
DOI:10.1039/p19800001436
日期:——
The basecatalysedrearrangements of diallylammonium rations and allylpropynylammonium rations are described. In most cases, the major product arises by a symmetry-allowed [3,2] sigmatropic rearrangement of the intermediateylide. The minor products can be regarded as being derived by homolysis of the ylide into a radical pair followed by recombination.
Tunable stereoselective alkene synthesis by treatment of activated imines with nonstabilized phosphonium ylides
作者:De-Jun Dong、Yuan Li、Jie-Qi Wang、Shi-Kai Tian
DOI:10.1039/c0cc04739b
日期:——
A broad range of readily accessible N-sulfonyl imines undergo olefination reaction with nonstabilized phosphoniumylides under mild conditions to afford an array of both Z- and E-isomers of 1,2-disubstituted alkenes, allylic alcohols, and allylic amines in good yields and with greater than 99 : 1 stereoselectivity.
Chain-Length- and Solvent-Dependent Intramolecular Proton Transfer in Styrene-Amine Exciplexes
作者:Frederick D. Lewis、G. Dasharatha Reddy、Dario M. Bassani、Siegfried Schneider、Michael Gahr
DOI:10.1021/ja00081a021
日期:1994.1
Efficient intramolecular addition of an aminomethyl C-H to styrene is observed in nonpolar. solvents for the (aminoethyl)styrenes, and addition of an aminomethylene C-H is observed for the (aminobutyl)styrenes. However, the (aminomethyl)- and (aminopropyl)styrenes do not undergo intramolecular addition reactions. Both the reactive and unreactive (aminoalkyl)styrenes form fluorescent singlet exciplexes in