"Pd/NHC-Catalyzed Enantiospecific and Regioselective Suzuki-Miyaura Arylation of 2-Arylaziridines: Synthesis of Enantioenriched 2-Arylphenethylamine Derivatives"

"Pd/NHC-Catalyzed Enantiospecific and Regioselective Suzuki-Miyaura Arylation of 2-Arylaziridines: Synthesis of Enantioenriched 2-Arylphenethylamine Derivatives"
Youhei Takeda*, Yuki Ikeda, Akinobu Kuroda, Shino Tanaka, and Satoshi Minakata*
J. Am. Chem. Soc. 2014, 136, 8544–8547. DOI: 10.1021/ja5039616 

* Highlighted in Org. Process Res. Dev. as "Some Items of Interest to Process R&D Chemists and Engineers"! !（link）
Abstract: A palladium-catalyzed stereospecific and regioselective cross-coupling of enantiopure 2-arylaziridines with arylboronic acids under mild conditions to construct a tertiary stereogenic center has been developed. N-heterocyclic carbene (NHC) ligands drastically promote the coupling, suppressing β-hydride elimination. The enantiospecific cross-coupling allowed us for preparation of a series of biologically important 2-arylphenethylamine derivatives in an enantiopure form.

Application of carbon dioxide to organic synthesis

Application of carbon dioxide to organic synthesis

Carbon dioxide fixation to unsaturated alcohols could be realized under extremely mild conditions by using tert-BuOI.



Angew. Chem. Int. Ed. 2010, 49, 1309.


Haloamidation of olefins induced by carbon dioxide was developed.

Org. Lett. 2006, 8, 967.　Org. Bio.mol. Chem. 2010, 8, 1424

Application of water/silica system to organic synthesis

Application of water/silica system to organic synthesis

Organic reactions on silica in water were successfully achieved by utilizing hydrophobic interaction.

Chem. Rev. 2009, 109, 711.　Angew. Chem. Int. Ed. 2004, 43, 79

Organic Synthesis: The Disconnection Approach

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Titania-catalysed oxidative dehydrogenation of ethyl lactate: effective yet selective free-radical oxidation

Titania-catalysed oxidative dehydrogenation of ethyl lactate: effective yet selective free-radical oxidation

http://pubs.rsc.org/en/Content/ArticleLanding/2014/GC/C4GC00191E?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+rss%2FGC+%28RSC+-+Green+Chem.+latest+articles%29#!divAbstract

Green Chem., 2014, 16,3358-3363
DOI: 10.1039/C4GC00191E, Paper

 Open Access

  This article is licensed under a Creative Commons Attribution 3.0 Unported Licence.

Enrique V. Ramos-Fernandez, Norbert J. Geels, N. Raveendran Shiju, Gadi Rothenberg
Set them free? Combining a solid catalyst and a solid free-radical scavenger, gives a free-radical oxidation that gives high selectivity even at high concentrations.


We research here the catalytic oxidative dehydrogenation of ethyl lactate, as an alternative route to ethyl pyruvate. Testing various solid catalysts (Fe₂O₃, TiO₂, V₂O₅/MgO–Al₂O₃, ZrO₂, CeO₂ and ZnO), we find that simple and inexpensive TiO₂ efficiently catalyses this reaction under mild conditions. Furthermore, molecular oxygen was used as the terminal oxidant. Importantly, this reaction runs well also using inexpensive commercial solvent mixtures. Both the desired reaction and the by-products formation follow a free-radical mechanism. Remarkably, adding activated carbon, a solid radical scavenger, hardly affects the catalytic activity, but enhances the product selectivity. This is because this solid radical scavenger hampers the formation of undesired products in solution, without suppressing the oxidation at the catalyst surface.

Oxyhalogenation of thiols and disulfides into sulfonyl chlorides/bromides using oxone-KX (X = Cl or Br) in water

A simple and rapid method for efficient synthesis of sulfonyl chlorides/bromides by oxyhalogenation of thiols and disulfides with oxone-KX (X = Cl or Br) using water as the solvent is described.

http://pubs.rsc.org/en/Content/ArticleLanding/2014/GC/C4GC00246F?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+rss%2FGC+%28RSC+-+Green+Chem.+latest+articles%29#!divAbstract

Green Chem., 2014, Advance Article
DOI: 10.1039/C4GC00246F, Paper

Sridhar Madabhushi, Raveendra Jillella, Vinodkumar Sriramoju, Rajpal Singh
A simple and efficient method for synthesis of sulfonyl chlorides/bromides by oxyhalogenation of thiols and disulfides with oxone-KX (X = Cl or Br) using water as the solvent is presented

Oxyhalogenation of thiols and disulfides into sulfonyl chlorides/bromides 

using oxone-KX (X = Cl or Br) in water

Recent advances on diversity oriented heterocycle synthesis via multicomponent tandem reactions based on A3 coupling

Recent advances on diversity oriented heterocycle synthesis via multicomponent tandem reactions based on A³ coupling (14-8183LR) [pp. 1-20]
Arkivoc 2014 Part (i), 1-20: Special Issue 'Reviews and Accounts'
Yunyun Liu
Full Text: PDF (235K)
http://www.arkat-usa.org/get-file/48824/
Recent advances on diversity oriented heterocycle synthesis via
multicomponent tandem reactions based on A3 coupling

Yunyun Liu*
a,b

a Key Laboratory of Functional Small Organic Molecule, Ministry of Education,
Jiangxi Normal University, Nanchang 330022, P. R. China
b College of Chemistry and Chemical Engineering, Jiangxi Normal University,
Nanchang 330022, P. R. China

Abstract
A3 coupling reactions are the reactions between aldehydes, amines and alkynes, which yield
propargylamine derivatives under various catalyst conditions. By making use of the versatile
reactivity of propargylamines, tandem reactions initiated by the functional group(s) in the in situ
generated propargylamines constitute one of the most important applications of A3
 couplings.
These tandem reactions are especially useful for the synthesis of heterocyclic compounds. In this
review, the progress on multicomponent tandem reactions based on A3
 coupling is summarized.



Author’s Biography


Dr. Yunyun Liu was born in 1983 in Shandong Province, China. She obtained her Bachelor
Degree in Qufu Normal University in 2005. She then moved to Zhejiang University to continue
her graduate study in the Department of Chemistry. Under the supervision of Professor Weiliang
Bao, she worked on the field of copper-catalyzed Ullmann coupling reaction and related tandem
reactions for her doctorate study. She obtained her doctorate degree in 2010 and presently she is
an assistant professor in Jiangxi Normal University. She is currently interested in the research of
metal-catalyzed organic synthesis and the development of new cascade organic reactions.

Cheaper Chlorination of Organic Compounds

Inexpensive hydrochloric acid is promising for low-cost electrochemical chlorination
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Cheaper Chlorination of Organic Compounds

Safer Methods for Carbonylative Coupling

Palladium-catalyzed carbonylative α-arylation of aryl bromides
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Safer Methods for Carbonylative Coupling

Building-Block Compounds from Iodoaldol Reactions

The iodoaldol reaction of internal alkynyl ketones gives useful oxygen-functionalized vinyl iodides
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Building-Block Compounds from Iodoaldol Reactions

Temsirolimus « New Drug Approvals

Temsirolimus « New Drug Approvals:

'via Blog this'

Here’s an improved synthesis of benzazepines

Benzazepines are heterocyclic chemical compounds consisting of a benzene ring fused to an azepinering. Examples include benazepril, fenoldopam, lorcaserin and varenicline

Benzazepines at the US National Library of Medicine Medical Subject Headings (MeSH)

Fenoldopam

Lorcaserin

Benzazepines such as compound 3are intermediates for synthesizing drugs used to treat heart and kidney disorders. Y. Torisawa and co-inventors state that existing methods for preparing the intermediates are inefficient for industrial production because of low yields and purity.

The route they used for preparing 3 is the reaction of chlorotetrahydrobenzazepine 1with bromoaniline derivative 2 in the presence of CO and a Pd–Ph3P catalyst (Figure 1); DBU is 1,8-diazabicyclo[5.4.0]undec-7-ene. The product is isolated, purified by column chromatography, and recovered in 85% yield and 99.1% purity. The patent contains 1H and 13C NMR, IR, and mass spectroscopy data.

The reaction gives small quantities (≈0.01–0.03 wt%) of four byproducts that are formed by the reaction of 3 with 1. These compounds are easily separated from 3, and their 1H NMR data are reported.

The inventors also describe the synthesis of 2 and several structurally related compounds by routes outlined in Figure 2. The preparation of 2 begins with the condensation of toluidine 4 and benzoyl chloride 5 in the presence of NaOH to form amide 6, isolated in 96.6% yield. In the second step, 6 is brominated in HOAc, and 2 is isolated in 97% yield. Although the purities of 2 and 6 are not reported, both have sharp melting points; 1H NMR data are provided.

Compound 6 can also be used to prepare acid 7 by treating it with (COCl)2 in the presence of AlCl3, and then hydrolyzing the product. The crude acid is isolated, treated with aq NaOH, and recovered in 65.8% yield and 99.4% purity after recrystallization from MeOH.

The reaction of 6 and AcCl in the presence of AlCl3 gives compound 8, isolated in 66.8% yield. The purity is not reported, but the compound has a sharp melting point, and 1H NMR data are given. Oxidizing 8 with NaOCl forms 7, which is isolated in 77.2% yield and 99.8% purity after recrystallization from MeOH.

A key feature of the processes described in this patent is the commercial availability of starting materials 1 and 2. The inventors claim that the processes give the desired compounds in higher yields and purities than existing methods. (Otsuka Pharmaceutical [Tokyo]. US Patent 8,273,735, )

Process for preparing benzazepine compounds or salts thereof

www.google.co.in/patents/US8273735

Grant - ‎Filed 1 Sep 2006 - ‎Issued 25 Sep 2012 - ‎Yasuhiro Torisawa - ‎Otsuka Pharmaceutical Co., Ltd.

This invention provides a process for preparing benzazepine compounds of the formula (1): wherein X1 is a halogen atom, R1 and ...

Paper | Regular issue | Vol 53, No. 9, 2000, pp.2009-2018
Published online: 

DOI: 10.3987/COM-00-8982

■ A Synthesis of 2,3,4,5-Tetrahydro-1H-3-benzazepines via Pummerer-Type Cyclization of N-(2-Arylethyl)-N-(2-phenylsulfinylethyl)formamides

Jun Toda, Tsuyoshi Ichikawa, Toshiaki Saitoh, Yoshie Horiguchi, and Takehiro Sano*

*Showa Pharmaceutical University, 3-3165, Higashi-tamagawagakuen, Machida, Tokyo 194-8543, Japan

Abstract

A construction of 2,3,4,5-tetrahydro-1H-3-benzazepine ring system (7) was achieved via Pummerer-type cyclization of N-(2-arylethyl)-N-2- (phenylsulfinylethyl)formamides (6). This route produced the benzazepines (10) and (11) in six steps starting from readily available 2-arylethylamines (2) and 2-chloroethyl phenyl sulfide. 

PDF (61KB)

Asymmetric Esterification for Total Synthesis

Production of chiral carboxylic esters proves a useful method in the total synthesis of centrolobine
Read more