34218-70-7Relevant academic research and scientific papers
Highly stereoselective cyclopropanation of diazo Weinreb amides catalyzed by chiral Ru(II)-: Amm -Pheox complexes
Chanthamath, Soda,Mandour, Hamada S. A.,Tong, Thu Minh Thi,Shibatomi, Kazutaka,Iwasa, Seiji
supporting information, p. 7814 - 7817 (2016/07/06)
The first highly stereoselective cyclopropanation of diazo Weinreb amides with olefins was accomplished using chiral Ru(ii)-Amm-Pheox complex 7a to give the corresponding chiral cyclopropyl Weinreb amides in high yields (up to 99%) with excellent diastereoselectivities (up to 99:1 dr) and enantioselectivities (up to 96% ee).
Tandem diastereo- and enantioselective preparation of aryl and alkyl cyclopropyl carbinols with three adjacent stereocenters using perhydrobenzoxazines and diethylzinc
Infante, Rebeca,Nieto, Javier,Andres, Celia
, p. 345 - 354 (2014/01/06)
The enantio- and diastereoselective one-pot ethylation/cyclopropanation is efficiently promoted by a chiral perhydrobenzoxazine. The catalytic system tolerates a wide range of di- and trisubstituted α,β-unsaturated aldehydes and has been found to be highly diastereo- and enantioselective. Enals leading to intermediates lacking allylic strain or with either A1,2 or A1,3 strain afford the corresponding syn hydroxycyclopropanes very selectively. While α-methyl enals are successfully ethylated/ cyclopropanated, the presence of bulky substituents at the alpha position of the enal constitutes a limitation to the substrate scope. The use of 1,1-diiodoethane allows the obtention of the corresponding enantioenriched cyclopropylcarbinol, which bears carbon-substituents at all three positions of the ring, with good enantiocontrol, although moderate diastereoselectivity. A procedure for the asymmetric one-pot arylation/cyclopropanation of enals is proposed, which involves the use of triarylboroxin, diethylzinc and diiodomethane.
Asymmetric intermolecular cyclopropanation of alkenes by diazoketones catalyzed by Halterman iron porphyrins
Nicolas, Irène,Roisnel, Thierry,Maux, Paul Le,Simonneaux, Gérard
scheme or table, p. 5149 - 5151 (2009/12/05)
The asymmetric addition of diazoacetophenone to styrene derivatives to give optically active cyclopropyl ketones (ee up to 80%) was carried out using chiral iron porphyrins as homogeneous catalysts. Intermolecular N-H functionalization of anilines by mean
Stereocontrol with phosphine oxides: Synthesis of optically active cyclopropyl ketones
Nelson, Adam,Warren, Stuart
, p. 3425 - 3433 (2007/10/03)
Treatment of -keto y'-hydroxy phosphine oxides, or silylated hemiacetal derivatives of these compounds, with potassium /e/7-butoxide in /e/7-butyl alcohol leads to the formation of cyclopropyl ketones. The synthesis of optically active 1, 2-di- and 1, 2,
