5921-73-3Relevant academic research and scientific papers
A synthesis of petrofuran based on the enantioselective reduction of 1- trimethylsilyl-4-alken-1-yn-3-ones
Garcia,López,Romeu
, p. 429 - 431 (1999)
Highly enantioenriched 4-alken-1-yn-3-ol moiety (1), present in many bioactive acetylenic metabolites from sponges, has been efficiently obtained by reduction of the parent 1-trimethylsilyl-4-alken-1-yn-3-one (2) with Alpine-Borane or with BH3 · SMe2 in the presence of chiral oxazaborolidines, followed by desilylation of the resulting alcohol. This strategy has been applied to the first stereoselective synthesis of petrofuran 3.
(ω-2,ω-2,ω-3,ω-3)-Tetradeuterio-fatty acids for mechanistic studies of enzyme-catalyzed hydroxylation reactions
Horner, John H.,Newcomb, Martin
, p. 406 - 410 (2012)
Among the thousands of cytochrome P450 enzymes known, many selectively hydroxylate the hydrocarbon tail of fatty acids at the terminal (ω) position and the ω-1, ω-2, and ω-3 positions. A general method for synthesis of (ω-2,ω-2,ω-3,ω-3)-tetradeuterio-fatty acids that can be used in mechanistic studies of cytochromes P450 is illustrated by the synthesis of 9,9,10,10-tetradueteriododecanoic (lauric) acid and 13,13,14,14-tetradeuteriohexadecanoic (palmitic) acid. Deuterium is introduced early in the synthesis by reduction of the THP ether of 4-heptyn-1-ol with deuterium gas to give a common labeled intermediate, 4,4,5,5- tetradeuterioheptan-1-ol. This alcohol is converted to the corresponding tosylate that is used to alkylate O-protected (ω-1)-alkyn-1-ols to give, eventually, long-chain alcohols that are oxidized to the corresponding fatty acids. An important experimental detail is that relatively large amounts of Wilkinson's catalyst were used to limit isotopic scrambling. Copyright
Catalytic Access to Functionalized Allylic gem-Difluorides via Fluorinative Meyer–Schuster-Like Rearrangement
An, Rui,Li, Huimin,Liao, Lihao,Wu, Jin-Ji,Xu, Yang,Zhao, Xiaodan
supporting information, p. 11010 - 11019 (2020/05/18)
An unprecedented approach for efficient synthesis of functionalized allylic gem-difluorides via catalytic fluorinative Meyer–Schuster-like rearrangement is disclosed. This transformation proceeded with readily accessible propargylic fluorides, and low-cost B–F reagents and electrophilic reagents by sulfide catalysis. A series of iodinated, brominated, and trifluoromethylthiolated allylic gem-difluorides that were difficult to access by other methods were facilely produced with a wide range of functional groups. Importantly, the obtained iodinated products could be incorporated into different drugs and natural products, and could be expediently converted into many other valuable gem-difluoroalkyl molecules as well. Mechanistic studies revealed that this reaction went through a regioselective fluorination of alkynes followed by a formal 1,3-fluorine migration under the assistance of the B–F reagents to give the desired products.
An unprecedented medium-chain diunsaturated n-acylhomoserine lactone from marine roseobacter group bacteria
Ziesche, Lisa,Wolter, Laura,Wang, Hui,Brinkhoff, Thorsten,Pohlner, Marion,Engelen, Bert,Wagner-D?bler, Irene,Schulz, Stefan
, (2019/01/11)
N-acylhomoserine lactones (AHLs), bacterial signaling compounds involved in quorum-sensing, are a structurally diverse group of compounds. We describe here the identification, synthesis, occurrence and biological activity of a new AHL, N-((2E,5Z)-2,5-dodecadienoyl)homoserine lactone (11) and its isomer N-((3E,5Z)-3,5-dodecadienoyl)homoserine lactone (13), occurring in several Roseobacter group bacteria (Rhodobacteraceae). The analysis of 26 strains revealed the presence of 11 and 13 in six of them originating from the surface of the macroalgae Fucus spiralis or sediments from the North Sea. In addition, 18 other AHLs were detected in 12 strains. Compound identification was performed by GC/MS. Mass spectral analysis revealed a diunsaturated C12 homoserine lactone as structural element of the new AHL. Synthesis of three likely candidate compounds, 11, 13 and N-((2E,4E)-2,4-dodecadienoyl)homoserine lactone (5), revealed the former to be the natural AHLs. Bioactivity test with quorum-sensing reporter strains showed high activity of all three compounds. Therefore, the configuration and stereochemistry of the double bonds in the acyl chain seemed to be unimportant for the activity, although the chains have largely different shapes, solely the chain length determining activity. In combination with previous results with other Roseobacter group bacteria, we could show that there is wide variance between AHL composition within the strains. Furthermore, no association of certain AHLs with different habitats like macroalgal surfaces or sediment could be detected.
Direct Access to Allenylphosphine Oxides via a Metal Free Coupling of Propargylic Substrates with P(O)H Compounds
Yang, Chun-Hua,Fan, Huihui,Li, Huimin,Hou, Shenyin,Sun, Xiangkun,Luo, Donghao,Zhang, Yinchao,Yang, Zhantao,Chang, Junbiao
supporting information, p. 9438 - 9441 (2019/11/20)
A direct and convenient approach for the coupling of propargylic substrates with diphenylphosphine oxide in the presence of Tf2O and 2,6-lutidine has been developed. The method provides a general approach for the construction of attractive allenylphosphoryl skeletons with high atom and step economy under metal free conditions.
Divergent gold-catalysed reactions of cyclopropenylmethyl sulfonamides with tethered heteroaromatics
Drew, Melanie A.,Arndt, Sebastian,Richardson, Christopher,Rudolph, Matthias,Hashmi, A. Stephen K.,Hyland, Christopher J. T.
supporting information, p. 13971 - 13974 (2019/11/25)
Cyclopropenylmethyl sulfonamides with tethered heteroaromatics have been demonstrated to undergo divergent gold-catalysed cyclisation reactions. A formal dearomative (4+3) cycloaddition takes place with furan-tethered substrates, yielding densely functionalised 5,7-fused heterocycles related to the bioactive curcusone natural products. Indole-tethered substrates display divergent reactivity giving biologically important tetrahydro-β-carbolines via a Friedel-Crafts mechanism.
Enantioselective Rhodium-Catalyzed Dimerization of ω-Allenyl Carboxylic Acids: Straightforward Synthesis of C2-Symmetric Macrodiolides
Steib, Philip,Breit, Bernhard
supporting information, p. 6572 - 6576 (2018/05/08)
Herein, we report on the first enantioselective and atom-efficient catalytic one-step dimerization method to selectively transform ω-allenyl carboxylic acids into C2-symmetric 14- to 28-membered bismacrolactones (macrodiolides). This convenient asymmetric access serves as an attractive route towards multiple naturally occuring homodimeric macrocyclic scaffolds and demonstrates excellent efficiency to construct the complex, symmetric core structures. By utilizing a rhodium catalyst with a modified chiral cyclopentylidene-diop ligand, the desired diolides were obtained in good to high yields, high diastereoselectivity, and excellent enantioselectivity.
Rhodium-catalyzed hydroformylation of 1,1-disubstituted allenes employing the self-assembling 6-DPPon system
K?pfer, Alexander,Breit, Bernhard
supporting information, p. 6913 - 6917 (2015/06/08)
Abstract A rhodium-catalyzed hydroformylation of 1,1-disubstituted allenes is reported. Using a RhI/6-DPPon catalyst system, one can obtain β,γ-unsaturated aldehydes in high regio- and chemoselectivity. The Z-configured product is formed with up to >95% selectivity when unsymmetrically 1,1-disubstituted allenes are submitted to the reaction conditions. This is the first time that these interesting building blocks are accessible by hydroformylation of allenes. The utility of this methodology is demonstrated by further transformations of one of the obtained products. β,γ-Unsaturated aldehydes are obtained by a rhodium-catalyzed hydroformylation of 1,1-disubstituted allenes. For unsymmetrically 1,1-disubstituted allenes the Z-configured product is formed in up to about 95% selectivity. This is the first time that these building blocks are accessible by hydroformylation of allenes. The utility of this methodology is demonstrated by further transformations of one of the obtained products.
The first convergent total synthesis of penarolide sulfate A2, a novel α-glucosidase inhibitor
Gao, Yangguang,Shan, Qiuli,Liu, Jun,Wang, Linlin,Du, Yuguo
, p. 2071 - 2079 (2014/03/21)
Penarolide sulfate A2, a 31-membered macrolide encompassing a proline residue and three sulfate groups, was firstly synthesized in 16 linear steps with 4.8% overall yield. Three consecutive stereogenic centers in penarolide sulfate A2 were efficiently derived from natural chiral template l-arabinose. The crucial assembly reactions included Brown asymmetric allylation, olefin cross-metathesis, alkyne-epoxide coupling, and macrolactamization. The anti-yeast α-glucosidase activities of penarolide sulfate A2 and its fully desulfated derivative were examined showing IC50 values of 4.87 and 10.74 μg mL-1, respectively.
Substrate scope and stereocontrol in the Rh(II)-catalysed oxyamination of allylic carbamates
Unsworth, William P.,Lamont, Scott G.,Robertson, Jeremy
, p. 7388 - 7394 (2017/09/12)
Application of a modified Du Bois protocol for rhodium-stabilised nitrenoid generation to a variety of allylic carbamates results in 4-acetoxymethyl-1,3-oxazolidin-2-one derivatives with moderate to high levels of stereocontrol.
