Substrate-controlled Diastereoselective Michael Addition of Alkylidene Malonates by Grignard Reagents
نویسندگان
چکیده
منابع مشابه
Cu(I)/TF-BiphamPhos-catalyzed asymmetric Michael addition of cyclic ketimino esters to alkylidene malonates.
Cu(I)-catalyzed asymmetric Michael addition of cyclic ketimino esters with alkylidene malonates has been developed for efficient construction of β-branched α-amino acids containing adjacent quaternary and tertiary stereogenic centers in good yields with excellent diastereo-/enantioselectivities. The generated Michael adduct was further converted to the biologically important pyrrolizidine analo...
متن کاملCatalytic enantioselective direct Michael additions of ketones to alkylidene malonates
Enantioselective direct Michael additions of ketones using (S)-1-(2-pyrrolidinylmethyl)-pyrrolidine as a catalyst are described. Michael adducts with up to 91% e.e. were obtained by the reaction of alkylidene malonates with simple unactivated ketones under mild reaction conditions. © 2001 Elsevier Science Ltd. All rights reserved. An increasing demand for optically active compounds has stimulat...
متن کاملEnantioselective Addition of Grignard Reagents to Aldehydes
The addition of Grignard reagents to aldehydes in the presence of chiral aminoalcohols shows a moderate enantioselectivity. The study carried out with a series of ligands allows the correlation between the structural characteristics and their reactivity. Introduction The use of chiral aminoalcohol to lead asymmetrically nucleophilic additions of organometallics to carbonyl compounds is a field ...
متن کامل"Anti-Michael addition" of Grignard reagents to sulfonylacetylenes: synthesis of alkynes.
In this work, the addition of Grignard reagents to arylsulfonylacetylenes, which undergoes an "anti-Michael addition", resulting in their alkynylation under very mild conditions is described. The simplicity of the experimental procedure and the functional group tolerance are the main features of this methodology. This is an important advantage over the use of organolithium at -78 °C that we pre...
متن کاملCatalytic enantioselective addition of Grignard reagents to aromatic silyl ketimines
α-Chiral amines are of significant importance in medicinal chemistry, asymmetric synthesis and material science, but methods for their efficient synthesis are scarce. In particular, the synthesis of α-chiral amines with the challenging tetrasubstituted carbon stereocentre is a long-standing problem and catalytic asymmetric additions of organometallic reagents to ketimines that would give direct...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Heterocyclic Communications
سال: 2019
ISSN: 2191-0197
DOI: 10.1515/hc-2019-0019