Direct Synthesis of Amides from Carboxylic Acids and Amines Using B(OCH<sub>2</sub>CF<sub>3</sub>)<sub>3</sub>
作者:Rachel M. Lanigan、Pavel Starkov、Tom D. Sheppard
DOI:10.1021/jo400509n
日期:2013.5.3
range of amines. In most cases, the amide products can be purified by a simple filtration procedure using commercially available resins, with no need for aqueous workup or chromatography. The amidation of N-protected amino acids with both primary and secondary amines proceeds effectively, with very low levels of racemization. B(OCH2CF3)3 can also be used for the formylation of a range of amines in good
Enantioselective α-Benzylation of Acyclic Esters Using π-Extended Electrophiles
作者:Kevin J. Schwarz、Chao Yang、James W. B. Fyfe、Thomas N. Snaddon
DOI:10.1002/anie.201806742
日期:2018.9.10
esters is reported. This reaction proceeds via stereodefined C1‐ammonium enolate nucleophiles. Critical to its success was the identification of benzylic phosphate electrophiles, which were uniquely reactive. Alkylated products were obtained with very high levels of enantioselectivity, and this method has been applied toward the synthesis of the thrombin inhibitor DX‐9065a.
Ligand exchange reaction of sulfoxides in organic synthesis: A versatile procedure for one-carbon homologation of methylesters to esters, thioesters, carboxylic acids and amides
A novel two-step procedure for one-carbon homologation of methylesters to esters, thioesters, carboxylic acids and amides is described. Methylesters are reacted with lithium carbanion of chloromethyl phenyl sulfoxide to give α-chloro α-sulfinyl ketones in 70 to 90% yields. Potassium enolate of the α-chloro α-sulfinyl ketone was treated with tert-butyllithium at −78 °C to give alkynolate via alkylidene
carboxylic acid and aminederivatives catalyzed by TiCp2Cl2. Arylacetic acid derivatives reacted with different amines to afford the corresponding amides in good to excellent yield except of aniline. Aryl formic acids failed to react with aniline but smoothly reacted with aliphatic amines and benzylamine in moderate to good yield, fatty acids reacting with benzyl and aliphatic amines give amides in good
CATALYTIC SYSTEMS FOR STEREOSELECTIVE SYNTHESIS OF CHIRAL AMINES BY ENANTIODIVERGENT RADICAL C-H AMINATION
申请人:Trustees of Boston College
公开号:US20200317627A1
公开(公告)日:2020-10-08
In one aspect, the disclosure relates to a mode of asymmetric induction in radical processes based on sequential combination of enantiodifferentiative H-atom abstraction and stereoretentive radical substitution. Also disclosed is an asymmetric system for stereoselective synthesis of strained 5-membered cyclic sulfamides via radical 1,5-C—H amination of sulfamoyl azides. The disclosed metalloradical system can control the degree and sense of asymmetric induction in the catalytic radical C—H amination in a systematic manner. The disclosed system is applicable to a broad scope of substrates with different types of C(sp
3
)-H bonds and exhibits reactivity and selectivity, providing access to both enantiomers of useful 5-membered cyclic sulfamides in a highly enantioenriched form. Also disclosed are catalysts useful in these processes. This abstract is intended as a scanning tool for purposes of searching in the particular art and is not intended to be limiting of the present disclosure.