Synthesis and 119Sn NMR of η1-O-coordinated sulphine-dimethyltin dichloride complexes and thermal CS and SO bond cleavage reactions: X-Ray structure (130 K) of Me2SnCl2[η-O-(Me(Ph)NC(Ph)SO)]

Reactions between Ru3(μ-H)(μ3-SBut)(CO)9 and dppm have given Ru3(μ-H)(μn- SBut)(μ-dppm)(CO)10-n(n = 2,3); hydrogenation of all three complexes resulted in S-C bond cleavage and formation of Ru3(μ-H)2(μ3-S)(CO)7(L2) [L2 = (CO)2, μ-dppm]. Facile substitution of 2CO in Ru3(μ-H)2(μ3-S)(CO)9 by dppm, dpam or ebdp (L2), catalysed by Na+[Ph2CO]- or [ppn][OAc], gave Ru3(μ-H)2(μ3-S)(μ-L2)(CO)7, in which the bis-tertiary phosphine (or arsine) bridges an edge of the Ru3 triangle, with the P (or As) atoms occupying equatorial positions. In the case of L2 = ebdp, this edge is also bridged by H, as shown by a single-crystal X-ray structure determination. Crystals of the title compound are mcnoclinic, space group P21/n, with unit cell parameters a 13.454(3), b 17.748(2), c 14.706(2) Ǻ, and β 94.50(1)°. The structure was refined by a full-matrix least-squares method; at convergence R and Rw were 0.036 and 0.038, respectively, for 4729 reflections with I ≥ 3.0σ(I).

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C-Glycoside metabolism in the gut and in nature: Identification, characterization, structural analyses and distribution of C-C bond-cleaving enzymes

Nature Communications ◽

10.1038/s41467-021-26585-1 ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Takahiro Mori ◽

Takuto Kumano ◽

Haibing He ◽

Satomi Watanabe ◽

Miki Senda ◽

...

Keyword(s):

Bond Cleavage ◽

Structural Basis ◽

Electron Microscopic ◽

Intestinal Microbes ◽

X Ray ◽

Sugar Moiety ◽

Structural Details ◽

Catalytic Mechanisms ◽

Cleavage Reactions ◽

Biochemical Analyses

AbstractC-Glycosides, in which a sugar moiety is linked via a carbon-carbon (C-C) bond to a non-sugar moiety (aglycone), are found in our food and medicine. The C-C bond is cleaved by intestinal microbes and the resulting aglycones exert various bioactivities. Although the enzymes responsible for the reactions have been identified, their catalytic mechanisms and the generality of the reactions in nature remain to be explored. Here, we present the identification and structural basis for the activation of xenobiotic C-glycosides by heterocomplex C-deglycosylation enzymes from intestinal and soil bacteria. They are found to be metal-dependent enzymes exhibiting broad substrate specificity toward C-glycosides. X-ray crystallographic and cryo-electron microscopic analyses, as well as structure-based mutagenesis, reveal the structural details of these enzymes and the detailed catalytic mechanisms of their remarkable C-C bond cleavage reactions. Furthermore, bioinformatic and biochemical analyses suggest that the C-deglycosylation enzymes are widely distributed in the gut, soil, and marine bacteria.

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Te–Te and Te–C bond cleavage reactions using a monovalent gallanediyl

Dalton Transactions ◽

10.1039/c5dt00172b ◽

2015 ◽

Vol 44 (11) ◽

pp. 5153-5159 ◽

Cited By ~ 14

Author(s):

Chelladurai Ganesamoorthy ◽

Georg Bendt ◽

Dieter Bläser ◽

Christoph Wölper ◽

Stephan Schulz

Keyword(s):

Ir Spectroscopy ◽

Single Crystal ◽

Heteronuclear Nmr ◽

Bond Cleavage ◽

X Ray ◽

Cleavage Reactions

Te–Te and Te–C bond cleavage occurs in reactions of monovalent LGa (L = [(2,6-i-Pr2-C6H3)NC(Me)]2CH) with Te, Ph2Te2 and i-Pr2Te. (LGa-μ-Te)21, LGa(TePh)22 and LGa(i-Pr)Tei-Pr 3 were characterized by heteronuclear NMR (1H, 13C, 125Te) and IR spectroscopy and by single crystal X-ray analyses.

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Novel W(CO)6-Promoted C-S Bond Cleavage Reactions of Dithianes. X-Ray Structure of 9,9′:9,9′-Terfluorene

Journal of the Chinese Chemical Society ◽

10.1002/jccs.199100006 ◽

1991 ◽

Vol 38 (1) ◽

pp. 35-38 ◽

Cited By ~ 6

Author(s):

Chi-Hong Kuo ◽

Tien-Yau Lnh ◽

Ming-Chu Cheng ◽

Shie-Ming Peng

Keyword(s):

Bond Cleavage ◽

X Ray ◽

Cleavage Reactions

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Hydrogenation-dehydrogenation and cleavage functions of hydrorefining catalysts studied by the reaction of tetrahydrothiophene

Collection of Czechoslovak Chemical Communications ◽

10.1135/cccc19862770 ◽

1986 ◽

Vol 51 (12) ◽

pp. 2770-2780 ◽

Cited By ~ 1

Author(s):

Alexandra Drahorádová ◽

Miroslav Zdražil

Keyword(s):

Activated Carbon ◽

Catalyst Surface ◽

Bond Cleavage ◽

Unsaturated Hydrocarbons ◽

Cleavage Reactions

The reaction of tetrahydrothiophene in a stream of nitrogen was used to study the relations between dehydrogenation and C-S cleavage reactions on sulphided Co-Mo/Al2O3 catalysts. The course of the reaction was compared for Co-Mo catalysts supported on alumina and activated carbon, for alumina alone as well as for a Pt/C catalyst. The effect of substitution of nitrogen for hydrogen, of the addition of water to the feed, of pre-sulphidation of catalysts and their deactivation by coking on the rate and selectivity of the reaction were also investigated. The results showed that hydrogenation-dehydrogenation and dehydrosulphurization activity of the sulphide catalysts have the same origin. Hydrogen accelerates dehydrosulphurization on the sulphide catalysts by removing sulphur and unsaturated hydrocarbons formed on catalyst surface by C-S bond cleavage reactions.

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Crystallization and preliminary X-ray characterization of the 2,4′-dihydroxyacetophenone dioxygenase fromAlcaligenessp. 4HAP

Acta Crystallographica Section F Structural Biology Communications ◽

10.1107/s2053230x14009649 ◽

2014 ◽

Vol 70 (6) ◽

pp. 823-826 ◽

Cited By ~ 4

Author(s):

G. Beaven ◽

A. Bowyer ◽

P. Erskine ◽

S. P. Wood ◽

A. McCoy ◽

...

Keyword(s):

Synchrotron Radiation ◽

Formic Acid ◽

Molecular Oxygen ◽

Aromatic Ring ◽

Bond Cleavage ◽

Its Sequence ◽

Hydroxybenzoic Acid ◽

X Ray

The enzyme 2,4′-dihydroxyacetophenone dioxygenase (or DAD) catalyses the conversion of 2,4′-dihydroxyacetophenone to 4-hydroxybenzoic acid and formic acid with the incorporation of molecular oxygen. Whilst the vast majority of dioxygenases cleave within the aromatic ring of the substrate, DAD is very unusual in that it is involved in C—C bond cleavage in a substituent of the aromatic ring. There is evidence that the enzyme is a homotetramer of 20.3 kDa subunits each containing nonhaem iron and its sequence suggests that it belongs to the cupin family of dioxygenases. By the use of limited chymotrypsinolysis, the DAD enzyme fromAlcaligenessp. 4HAP has been crystallized in a form that diffracts synchrotron radiation to a resolution of 2.2 Å.

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