- Addition of the Lithium Anion of Diphenylmethanol Methyl/Methoxymethyl Ether to Nonracemic Sulfinimines: Two-Step Asymmetric Synthesis of Diphenylprolinol Methyl Ether and Chiral (Diphenylmethoxymethyl)amines
-
Addition of the lithium anion generated from diphenylmethanol methyl and methoxymethyl ether to nonracemic sulfinimines afforded the corresponding addition products in excellent diastereoselctivity and yields. Deprotection of the MOM as well as sulfinyl groups rendered the enantiopure (diphenylhydroxymethyl)amines in excellent yields. The procedure was applied for a two-step synthesis of diphenylprolinol, a privileged ligand in asymmetric catalysis.
- Reddy, Arava Amaranadha,Prasad, Kavirayani R.
-
p. 10776 - 10785
(2018/09/12)
-
- Stereochemical lability of azatitanacyclopropanes: Dynamic kinetic resolution in reductive cross-coupling reactions with allylic alcohols
-
Azatitanacyclopropanes (titanaziridines) are shown to be stereochemically labile under reaction conditions for reductive cross-coupling. This fundamental property has been employed to realize highly selective asymmetric coupling reactions with allylic alcohols that proceed by dynamic kinetic resolution. The Royal Society of Chemistry 2013.
- Yang, Dexi,Micalizio, Glenn C.
-
supporting information
p. 8857 - 8859
(2013/09/24)
-
- Titanium-mediated cross-coupling reactions of imines with ketones or aldehydes: An efficient route for the synthesis of 1,2-amino alcohols
-
The cross-coupling reactions of imines with ketones using Ti(O iPr)4/c-C5H9MgCl reagent lead to 1,2-amino alcohols after hydrolysis. The coupling reactions with aldehydes could also afford 1,2-amino alcohols, however, in some cases, aziridines were obtained as major products in a stereoselective manner.
- Fan, Guoqin,Liu, Yuanhong
-
p. 5084 - 5087
(2012/09/25)
-
- New phenylglycine-derived primary amine organocatalysts for the preparation of optically active warfarin
-
In this work we present new, fully synthetic phenylglycinederived primary amine organocatalysts useful, for the onestep preparation, of optically active warfarin, an. important anticoagulant. Both enantiomeric forms of the catalysts are equally available and can be prepared by robust procedures without recourse to chromatographic purification. Together with a co-catalyst, particularly acetic acid or2,4-dinitrophen- ol, they can furnish warfarin in approximately 80 % ee and represent inexpensive alternatives to other primary amine organocatalysts such as the chiral diamines and. Cinchona-derived primary amines.
- Kristensen, Tor E.,Vestli, Kristian,Hansen, Finn K.,Hansen, Tore
-
experimental part
p. 5185 - 5191
(2010/01/11)
-
- Synthesis of heavily substituted 1,2-amino alcohols in enantiomerically pure form
-
A simple and convenient methodology for the preparation of optically pure 2-amino-2-aryl-1,1-diphenylethanols is presented. Allylamine was found to produce the ring-opening of triaryloxiranes in a regioselective and a stereospecific fashion. Removal of the allyl protecting group provided the free 1,2-amino alcohols in enantiomerically pure form.
- Garcia-Delgado, Noemi,Reddy, Katamreddy Subba,Sola, Lluis,Riera, Antoni,Pericas, Miquel A.,Verdaguer, Xavier
-
p. 7426 - 7428
(2007/10/03)
-
- Synthesis and structure determination of novel chiral imine-alkoxytitanium complexes
-
The imines 4 containing a diphenylcarbinol moiety serve as chiral ligands in novel enantiomerically pure imine-alkoxytitanium(IV) complexes. Depending on the molar ratio of the starting materials, imines 4 and titanium tetraisopropoxide, mono-chelated complexes 5 or bis-chelated complexes 6/7 result. The latter are formed diastereoselectively and the isomers 6 are main or exclusive products. Their (A) configuration is determined by a crystal-structure analysis of 6b. The bis-ligand complexes 6 or mixtures of 6/7, which are found to be remarkably stable, are used as precursors not only for the reactive dihalo complexes 8a/8b but also for the preparation of the mixed chloroisopropoxytitanium complex 8c.
- Fleischer, Ralf,Wunderlich, Hartmut,Braun, Manfred
-
p. 1063 - 1070
(2007/10/03)
-
- Asymmetric Induction in Intramolecular SN2' Reaction. Enantioselective Synthesis of Cyclopenta[b]benzofuran with Chiral Lithium Alkoxides
-
An enantioselective intramolecular cyclization of the bis-phenyllithium species 3 was attained by addition of chiral lithium alkoxides to produce a cyclopenta[b]benzofuran 2 with high % ee's up to 87 %.
- Nishiyama, Hisao,Sakata, Naoya,Motoyama, Yukihiro,Wakita, Hisanori,Nagase, Hiroshi
-
p. 1147 - 1148
(2007/10/03)
-