ChemInform Abstract: A Stereoselective Method for the Direct Preparation of 2′- Deoxycytidine

ChemInform ◽  
2010 ◽  
Vol 28 (35) ◽  
pp. no-no
Author(s):  
D. P. KJELL
Keyword(s):  
Stereoselective Method ◽  
Direct Preparation

A Mild and Simple Method for Making MIDA Boronates

2020 ◽  
Author(s):  
Aidan Kelly ◽  
Peng-Jui (Ruby) Chen ◽  
Jenna Klubnick ◽  
Daniel J. Blair ◽  
Martin D. Burke
Keyword(s):  
Organic Synthesis ◽  
Boronic Acids ◽  
Simple Method ◽  
Direct Preparation ◽  
Synthesis Procedure ◽  
Harsh Conditions

<div> <div> <div> <p>Existing methods for making MIDA boronates require harsh conditions and complex procedures to achieve dehydration. Here we disclose that a pre-dried form of MIDA, MIDA anhydride, acts as both a source of the MIDA ligand and an in situ desiccant to enable a mild and simple MIDA boronate synthesis procedure. This method expands the range of sensitive boronic acids that can be converted into their MIDA boronate counterparts. Further utilizing unique properties of MIDA boronates, we have developed a MIDA Boronate Maker Kit which enables the direct preparation and purification of MIDA boronates from boronic acids using only heating and centrifuge equipment that is widely available in labs that do not specialize in organic synthesis. </p> </div> </div> </div>

α-Ketophosphonates in the Synthesis of α-iminophosphonates

2020 ◽  
Vol 7 (2) ◽  
pp. 226-238
Author(s):  
Petro P. Ony`sko ◽  
Tetyana I. Chudakova ◽  
Vladimir V. Pirozhenko ◽  
Alexandr B. Rozhenko
Keyword(s):  
Bond Cleavage ◽  
Direct Synthesis ◽  
Equilibrium Mixture ◽  
Primary Amines ◽  
Alkyl Amines ◽  
Protic Solvents ◽  
Metallic Salts ◽  
Direct Preparation ◽  
Stage Synthesis ◽  
Aprotic Dipolar Solvent

The potentialities of condensation of α-ketophosphonates with primary amines for direct synthesis of α-iminophosphonates have been revealed. Diesters of α-ketophosphonic acids react with the primary amines by two competitive pathways: with a formation of α-iminophosphonates or a C-P bond cleavage resulting in a hydrogen phosphonate and an acylated amine. In many cases, the latter undesirable pathway is dominant, especially for more nucleophilic alkyl amines. Using metallic salts of α-ketophosphonates avoids the C-P bond cleavage, allowing direct preparation of α-phosphorylated imines by the reaction with primary amines. This strategy provides an atom economy single-stage synthesis of iminophosphonates – precursors of bio relevant phosphorus analogs of α-amino acids. Methyl sodium iminophosphonates, bearing aryl or heteryl substituents at the imino carbon atom exist in solutions at room temperature as an equilibrium mixture of Z- and E-isomers. A configuration of the C=N bond can be controlled by the solvent: changing the aprotic dipolar solvent DMSO-d6 by water or alcohols leads to the change from a predominant Z-isomer to almost an exclusive E-form. In contrast, diesters of the respective iminophosphonates exist in non-protic solvents predominantly in Econfiguration. The solvent effect on E-Z stereochemistry is demonstrated by DFT calculations.

Direct preparation of polyfunctional amino-substituted arylmagnesium reagents via an iodine–magnesium exchange reaction

2003 ◽  
pp. 396-397 ◽  
Author(s):  
Greta Varchi ◽  
Christiane Kofink ◽  
David M. Lindsay ◽  
Alfredo Ricci ◽  
Paul Knochel
Keyword(s):  
Exchange Reaction ◽  
Direct Preparation ◽  
Magnesium Exchange

Regio- and stereoselective method for the synthesis of 6?,7?-methylene-6,7-dihydrothebaine

1994 ◽  
Vol 43 (3) ◽  
pp. 509-510
Author(s):  
S. Z. Sultanov ◽  
V. A. Dokichev ◽  
E. E. Shults ◽  
U. M. Dzhemilev ◽  
G. A. Tolstikov ◽  
...  
Keyword(s):  
Stereoselective Method

Direct Preparation of Mesophase Pitch from Naphthalene by the Aid of HF/BF3

1989 ◽  
Vol 18 (11) ◽  
pp. 1893-1896 ◽  
Author(s):  
Isao Mochida ◽  
Kiyoyuki Shimizu ◽  
Yozo Korai ◽  
Yukio Sakai ◽  
Susumu Fujiyama
Keyword(s):  
Mesophase Pitch ◽  
Direct Preparation

A Stereoselective method to (E)- and (Z)-fluorovinyl phosphonates Utilizing Palladium(0) coupling methodology

1993 ◽  
Vol 34 (45) ◽  
pp. 7197-7200 ◽  
Author(s):  
Raymond S. Gross ◽  
Shujaath Mehdi ◽  
James R. McCarthy
Keyword(s):  
Stereoselective Method

Direct preparation and G-banding of chromosomes of mouse liver cells

1986 ◽  
Vol 164 (3) ◽  
pp. 177-181 ◽  
Author(s):  
Håvard Danielsen ◽  
Mette Lier ◽  
Anton Brøgger ◽  
Albrecht Reith
Keyword(s):  
Mouse Liver ◽  
Liver Cells ◽  
Direct Preparation
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