Catalytic Enantioselective Synthesis of Tertiary Thiols From 5<i>H</i>-Thiazol-4-ones and Nitroolefins: Bifunctional Ureidopeptide-Based Brønsted Base Catalysis
Fully loaded: The ureidopeptide‐basedbifunctionalBrønstedbase 1 efficiently promotes the first direct catalytic Michael reaction of α‐mercapto carboxylate surrogates with nitroolefins involving a fully substituted α‐carbon atom construction.
Ureidopeptide‐Based Brønsted Bases: Design, Synthesis and Application to the Catalytic Enantioselective Synthesis of β‐Amino Nitriles from (Arylsulfonyl)acetonitriles
作者:Saioa Diosdado、Rosa López、Claudio Palomo
DOI:10.1002/chem.201304877
日期:2014.5.19
preparation of β‐aminonitriles. We present a highly efficient organocatalytic methodology for the stereoselective synthesis of β‐aminonitriles, in which the key to success is the use of ureidopeptide‐basedBrønstedbase catalysts in combination with (arylsulfonyl)acetonitriles as synthetic equivalents of the acetonitrile anion. The method gives access to a variety of β‐aminonitriles with good yields
Direct Catalytic Asymmetric Mannich Reactions for the Construction of Quaternary Carbon Stereocenters
作者:Barry M. Trost、Tanguy Saget、Chao-I (Joey) Hung
DOI:10.1021/jacs.6b01187
日期:2016.3.23
Mannich reaction using α-branched ketones as nucleophilic partners for the direct enantio- and diastereoselective construction of quaternary carbon stereocenters. The reaction can be run on a gram-scale with a low catalyst loading without impacting its efficiency. Moreover, the Mannich adducts can be further elaborated with complete diastereocontrol to access molecules possessing complex stereotriads.
Strategy for Stereoselective Metal-free α-Functionalization of 2-Azaaryl Acetates with <i>N</i>
-Boc Imines
作者:Iñaki Bastida、Marcos San Segundo、Rosa López、Claudio Palomo
DOI:10.1002/chem.201703748
日期:2017.9.27
We report the first diastereo‐ and enantioselective formal Mannich reaction of 2‐pyridyl acetates which gives rise to α‐ and β‐functionalized 2‐substituted pyridines. Key for success is the previous azaarene N‐oxide formation enabling α‐carbon deprotonation by a mild bifunctional Brønsted base and subsequent reaction with N‐Boc imines under almost perfect stereocontrol.