A cation-directed two-component cascade approach to enantioenriched pyrroloindolines
作者:Jamie R. Wolstenhulme、Alex Cavell、Matija Gredičak、Russell W. Driver、Martin D. Smith
DOI:10.1039/c4cc06683a
日期:——
A cascade approach to complex pyrroloindolines bearing all-carbon quaternary stereocentres has been developed. This two-component process uses a chiral ammonium salt to control diastereo- and enantioselectivity in the addition of isocyanides to functionalized alkenes to afford pyrroloindolines with up to three stereocentres. A mechanistic proposal involving intramolecular hydrogen bond activation of the isocyanide is described.
Phase-Transfer-Catalysed Synthesis of Pyrroloindolines and Pyridoindolines by a Hydrogen-Bond-Assisted Isocyanide Cyclization Cascade
作者:Peter C. Knipe、Matija Gredičak、Artiom Cernijenko、Robert S. Paton、Martin D. Smith
DOI:10.1002/chem.201400192
日期:2014.3.10
stereocentre. Quantum chemical calculations demonstrated that intramolecular general acid catalysis plays a key accelerating role through stabilization of developing charge in the transition state, and that the reaction is best described as a 5‐endo dig cyclization, rather than an anionic 6πelectrocyclization. Investigations employing chiral phase‐transfer catalysts have given promising selectivities
Experiments on the <i>Chaperon</i> Effect in the Nitration of Aromatics
作者:Paolo Strazzolini、Angelo G. Giumanini、Antonio Runcio、Massimo Scuccato
DOI:10.1021/jo9709763
日期:1998.2.1
A nitro group may be effectively delivered to the ortho position of alkylbenzenes, provided that a suitable chaperon function is located in alpha-position and a dilute solution of HNO3 in CH2Cl2 is used. The carbonyl function of an aldehyde or ketone is the best choice, but a carboxyl, alkoxycarbonyl, and amide groups all work well. The ether function showed a less pronounced or tho orientation effect, whereas the hydroxyl group was too prone to oxidation. Side reactions were minimal under the conditions employed. A para chaperon effect was seemingly at work in the CH2Cl2 nitration of benzenepropanenitrile. All the results mere compared with the corresponding classical nitration in H2SO4.
GARCIA, J.;GREENHOUSE, R.;MUCHOWSKI, J. M.;RUIZ, J. A., TETRAHEDRON LETT., 1985, 26, N 15, 1827-1830
作者:GARCIA, J.、GREENHOUSE, R.、MUCHOWSKI, J. M.、RUIZ, J. A.
DOI:——
日期:——
Enantioselective Synthesis of <i>trans</i>
-2,3-Dihydro-1<i>H</i>
-indoles Through C-H Insertion of α-Diazocarbonyl Compounds
作者:Micol Santi、Simon T. R. Müller、Ana A. Folgueiras-Amador、Alexander Uttry、Paul Hellier、Thomas Wirth
DOI:10.1002/ejoc.201700412
日期:2017.4.10
A stereoselective synthesis of 2,3-dihydro-1H-indoles with a RhII-catalyzed C–H insertion is reported. The α-diazo carbonyl intermediates can be obtained by a diazo-transfer reaction of 2-aminophenylacetic acids. Optimization and kinetic studies were performed, which resulted to increased yields of the diazo transfer after mechanistic evaluation of the side-product formation. trans-2,3-Dihydro-1H-indoles