Palladium catalyzed C(sp3)–H acetoxylation of aliphatic primary amines to γ-amino alcohol derivatives

2017 ◽  
Vol 4 (11) ◽  
pp. 2097-2101 ◽  
Author(s):  
Kang Chen ◽  
Ding Wang ◽  
Zhao-Wei Li ◽  
Zheng Liu ◽  
Fei Pan ◽  
...  
Keyword(s):  
Amino Alcohol ◽  
Primary Amines ◽  
Amino Groups ◽  
Palladium Catalyzed ◽  
Primary Amino ◽  
Directing Group

It still remains a major challenge to apply free primary amino groups as the directing group for aliphatic C–H functionalization.

scholarly journals Dithiocarbamylation in histochemistry: carbon disulfide as a reagent for the visualization of primary amino groups with the light and electron microscope.

1980 ◽  
Vol 28 (6) ◽  
pp. 499-506 ◽  
Author(s):  
C J Tandler
Keyword(s):  
Lead Sulfide ◽  
Lead Acetate ◽  
Plant Root ◽  
Primary Amines ◽  
Distilled Water ◽  
Amino Groups ◽  
Root Tips ◽  
Sulfide Deposits ◽  
Primary Amino ◽  
Formalin Fixed

Tissue amino groups undergo dithiocarbamylation on treatment (12 hr, 22-25 degrees C) with a carbon disulfide:triethylamine:tetrahydrofuran (1:1:0.5, v/v) mixture. After washing with tetrahydrofuran:triethylamine (4:1, v/v) followed by tetrahydrofuran:pyridine (4:1,v/v) and ice-cold distilled water tissues were immersed into ice-cold 10% (w/v) lead acetate to yield yellowish lead dithiocarbamates. At 22-25 degrees C the derivatives obtained from primary amines decompose to lead sulfide. After washing with 5% lead acetate in 10% acetic acid followed by three changes of distilled water tissues are dehydrated and embedded in paraffin or Maraglas as usual. In proteins the reaction is given by the epsilon-amino group of lysine and alpha-terminal amino groups, while nucleic acids do not react. Results are shown in tetrahydrofuran-delipidized ethanol or formalin-fixed 1) plant root tips where brown-colored and electron-dense lead sulfide deposits are localized in condensed chromatin and chromosomes attributable to lysine-rich histones and 2) rat skeletal muscle where an interfibrillar component is visualized in a repeating pattern, possibly related to terminal regions of the sarcoplasmic reticulum.

Aldehyde gold clusters for molecular labeling

1995 ◽  
Vol 53 ◽  
pp. 858-859
Author(s):  
James F. Hainfeld ◽  
Frederic R. Furuya
Keyword(s):  
Covalent Bond ◽  
Aldehyde Group ◽  
Gold Clusters ◽  
Side Reactions ◽  
Amino Groups ◽  
Sodium Cyanoborohydride ◽  
Schiff’S Base ◽  
Protein Molecules ◽  
Hydroxysuccinimide Esters ◽  
Primary Amino

Glutaraldehyde is a useful tissue and molecular fixing reagents. The aldehyde moiety reacts mainly with primary amino groups to form a Schiff's base, which is reversible but reasonably stable at pH 7; a stable covalent bond may be formed by reduction with, e.g., sodium cyanoborohydride (Fig. 1). The bifunctional glutaraldehyde, (CHO-(CH2)3-CHO), successfully stabilizes protein molecules due to generally plentiful amines on their surface; bovine serum albumin has 60; 59 lysines + 1 α-amino. With some enzymes, catalytic activity after fixing is preserved; with respect to antigens, glutaraldehyde treatment can compromise their recognition by antibodies in some cases. Complicating the chemistry somewhat are the reported side reactions, where glutaraldehyde reacts with other amino acid side chains, cysteine, histidine, and tyrosine. It has also been reported that glutaraldehyde can polymerize in aqueous solution. Newer crosslinkers have been found that are more specific for the amino group, such as the N-hydroxysuccinimide esters, and are commonly preferred for forming conjugates. However, most of these linkers hydrolyze in solution, so that the activity is lost over several hours, whereas the aldehyde group is stable in solution, and may have an advantage of overall efficiency.

Stereospecific, Palladium-catalyzed C(sp3)–H Alkenylation and Alkynylation of a Proline Derivative Enabled by 8-Aminoquinoline as a Directing Group

2020 ◽  
Author(s):  
Aleksandra Balliu ◽  
Aaltje Roelofje Femmigje Strijker ◽  
Michael Oschmann ◽  
Monireh Pourghasemi Lati ◽  
Oscar Verho
Keyword(s):  
Carboxylic Acid ◽  
Building Blocks ◽  
Wide Range ◽  
Palladium Catalyzed ◽  
Directing Group ◽  
High Yields ◽  
Vinyl Iodides ◽  
Initial Results

<p>In this preprint, we present our initial results concerning a stereospecific Pd-catalyzed protocol for the C3 alkenylation and alkynylation of a proline derivative carrying the well utilized 8‑aminoquinoline directing group. Efficient C–H alkenylation was achieved with a wide range of vinyl iodides bearing different aliphatic, aromatic and heteroaromatic substituents, to furnish the corresponding C3 alkenylated products in good to high yields. In addition, we were able show that this protocol can also be used to install an alkynyl group into the pyrrolidine scaffold, when a TIPS-protected alkynyl bromide was used as the reaction partner. Furthermore, two different methods for the removal of the 8-aminoquinoline auxiliary are reported, which can enable access to both <i>cis</i>- and <i>trans</i>-configured carboxylic acid building blocks from the C–H alkenylation products.</p>

Purification of Penicillin Amidohydrolase, an Enzyme for Semisynthetic Procedures

1992 ◽  
Vol 57 (10) ◽  
pp. 2187-2191 ◽  
Author(s):  
Jiří Jiráček ◽  
Tomislav Barth ◽  
Jiří Velek ◽  
Ivo Bláha ◽  
Jan Pospíšek ◽  
...  
Keyword(s):  
Affinity Chromatography ◽  
Amino Groups ◽  
Primary Amino

Penicillin amidohydrolase (EC 3.5.1.11.) is one of the few enzymes used successfully for deprotection of primary amino groups of semisynthetic peptides. The available material is usually contamined by endo- and exopeptidases. We managed to prepare the enzyme devoid of trypsin- and chymotrypsin-like activities using affinity chromatography with specific ligands: Gly-D-Phe-Phe-Tyr-Thr-Pro-Lys-Thr (the fF peptide) and Leu-Gly-Val-D-Arg-Arg-Gly-Phe (the rR peptide). For further purification of the enzyme affinity chromatography with N-phenylacetyl-D-tert-Leu as a ligand was used.

Temporary (PO) directing group enabled carbazole ortho arylation via palladium catalysis

2021 ◽  
Vol 57 (16) ◽  
pp. 2021-2024
Author(s):  
Zhi-Chao Qi ◽  
Qin-Xin Lou ◽  
Yuan Niu ◽  
Shang-Dong Yang
Keyword(s):  
Palladium Catalysis ◽  
Palladium Catalyzed ◽  
Directing Group

An efficient palladium-catalyzed, temporary P(O) directing group assisted C–H bond arylation of carbazoles was achieved, accompanied by the directing group being self-shed spontaneously.

Intermolecular C–H Amidation of Alkenes with Carbon Monoxide and Azides via Tandem Palladium Catalysis

Synthesis ◽  
2021 ◽  
Author(s):  
Zheng-Yang Gu ◽  
Yang Wu ◽  
Feng Jin ◽  
Bao Xiaoguang ◽  
Ji-Bao Xia
Keyword(s):  
Carbon Monoxide ◽  
Palladium Catalysis ◽  
Computational Studies ◽  
Organic Azides ◽  
Reaction Proceeds ◽  
Palladium Catalyzed ◽  
Directing Group ◽  
And Control

An atom- and step-economic intermolecular multi-component palladium-catalyzed C–H amidation of alkenes with carbon monoxide and organic azides has been developed for the synthesis of alkenyl amides. The reaction proceeds efficiently without an ortho-directing group on the alkene substrates. Nontoxic dinitrogen is generated as the sole by-product. Computational studies and control experiments have revealed that the reaction takes place via an unexpected mechanism by tandem palladium catalysis.

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