@article { ISI:000229484600033, title = {Stereoselective syntheses of (+)-alpha- and (-)-beta-conhydrine from L-aspartic acid}, journal = {Tetrahedron Letters}, volume = {46}, number = {23}, year = {2005}, month = {JUN}, pages = {4091-4093}, publisher = {PERGAMON-ELSEVIER SCIENCE LTD}, type = {Article}, address = {THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND}, abstract = {

An efficient synthesis of (+)-alpha-conhydrine 1 and (-)-beta-conhydrine 2 has been achieved by. diastereo selective alkylation of an amino aldehyde derivative 7 with ethylmagnesium bromide or diethylzinc. (c) 2005 Elsevier Ltd. All rights reserved.

}, keywords = {Alkylation, conhydrine, Grignard reaction, Piperidine alkaloids, stereoselectivity}, issn = {0040-4039}, doi = {10.1016/j.tetlet.2005.04.013}, author = {Pandey, SK and Kumar, P} } @article { ISI:000231406400013, title = {Stereoselective syntheses of (+)-proto, (-)-gala quercitols and carba-L-rhamnose from D-(-)-quinic acid}, journal = {Tetrahedron Letters}, volume = {46}, number = {37}, year = {2005}, month = {SEP}, pages = {6235-6238}, publisher = {PERGAMON-ELSEVIER SCIENCE LTD}, type = {Article}, address = {THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND}, abstract = {

Efficient syntheses of (+)-proto, (-)-gala quercitols and carba-L-rhamnose front D-(-)-quinic acid are described. (c) 2005 Elsevier Ltd. All rights reserved.

}, keywords = {(+)-proto quercitol, (-)-gala quercitol, carba-L-rhamnose, cyclohexanepentols, D-(-)-quinic acid, stereoselectivity}, issn = {0040-4039}, doi = {10.1016/j.tetlet.2005.07.052}, author = {Murugan, A. Vadivel and Yadav, A. K. and Gurjar, M. K.} } @article { ISI:000233089900009, title = {Wittig-horner approach for the synthesis of tamoxifen}, journal = {Synthetic Communications}, volume = {35}, number = {21}, year = {2005}, month = {MAY}, pages = {2795-2800}, publisher = {TAYLOR \& FRANCIS INC}, type = {Article}, address = {325 CHESTNUT ST, SUITE 800, PHILADELPHIA, PA 19106 USA}, abstract = {

A stereoselective synthesis of Z -tamoxifen, a tetra-substituted alkene with antiestrogenic activity, is described. The Wittig-Horner reaction has been employed as the key step to establish the olefin stereochemistry.

}, keywords = {anticancer drug, phosphonate, stereoselectivity, Tamoxifen, Wittig-Horner reaction}, issn = {0039-7911}, doi = {10.1080/00397910500290516}, author = {Pandey, RK and Wakharkar, RD and Kumar, P} } @article { ISI:000269337500025, title = {Stereoselective construction of steroidal side chain from 16-dehydropregnenolone acetate}, journal = {Synlett}, number = {12}, year = {2009}, month = {JUL}, pages = {2005-2009}, publisher = {GEORG THIEME VERLAG KG}, address = {RUDIGERSTR 14, D-70469 STUTTGART, GERMANY}, abstract = {

Stereoselective construction of steroidal side chain at C-20 having {\textquoteleft}natural{\textquoteright} configuration using 16-dehydropregnalone acetate (16-6PA) as a starting material has been carried out. Palladium-catalyzed carbon-carbon bond-forming Heck reaction between C-20 vinyl iodide with methyl acrylate and transfer hydrogenation with triethylsilane and Pd/C are the key steps for stereoselective side-chain synthesis.

}, keywords = {16-dehydropregnenolone acetate, Heck coupling, stereoselectivity, steroidal side chain, transfer hydrogenation}, issn = {0936-5214}, doi = {10.1055/s-0029-1217521}, author = {Aher, Nilkanth G. and Gonnade, Rajesh G. and Pore, Vandana S.} } @article { ISI:000267070700082, title = {Tethered aminohydroxylation route to L-arabino-[2R,3S,4R] and L-xylo-[2R,3S,4S]-C-18-phytosphingosines}, journal = {Tetrahedron Letters}, volume = {50}, number = {26, SI}, year = {2009}, month = {JUL}, pages = {3425-3427}, publisher = {PERGAMON-ELSEVIER SCIENCE LTD}, address = {THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND}, abstract = {

A concise and highly efficient synthesis of L-arabino-[2R,3S,4R] and L-xylo-[ 2R,3S,4S]-C-18-phytosphingosines has been achieved. The synthetic strategy features the Sharpless kinetic resolution and tethered aminohydroxylation as the key steps. (C) 2009 Elsevier Ltd, All rights reserved.

}, keywords = {Phytosphingosine, Regioselectivity, Sharpless asymmetric kinetic resolution, Sphingolipids, stereoselectivity, Tethered aminohydroxylation}, issn = {0040-4039}, doi = {10.1016/j.tetlet.2009.02.173}, author = {Dubey, Abhishek and Kumar, Pradeep} } @article { ISI:000381182700004, title = {Spectacular rate enhancement of the diels-alder reaction at the ionic liquid/n-hexane interface}, journal = {Chemphyschem}, volume = {17}, number = {13}, year = {2016}, month = {JUL}, pages = {1969-1972}, publisher = {WILEY-V C H VERLAG GMBH}, address = {POSTFACH 101161, 69451 WEINHEIM, GERMANY}, abstract = {

The use of the ionic liquid/n-hexane interface as a new class of reaction medium for the Diels-Alder reaction gives large rate enhancements of the order of 10(6) to 10(8) times and high stereoselectivity, as compared to homogeneous media. The rate enhancement is attributed to the H-bonding abilities and polarities of the ionic liquids, whereas the hydrophobicity of ionic liquids was considered to be the factor in controlling stereoselectivity.

}, keywords = {Diels-Alder reaction, Interfaces, ionic liquids, kinetics, stereoselectivity}, issn = {1439-4235}, doi = {10.1002/cphc.201600006}, author = {Beniwal, Vijay and Manna, Arpan and Kumar, Anil} } @article {49126, title = {Chloroperoxidase applications in chemical synthesis of industrial relevance}, journal = {Biocatalysis and Biotransformation}, volume = {41}, year = {2023}, month = {NOV }, pages = {403-420}, type = {Article}, abstract = {

Biocatalysts can accelerate the catalysis of a chemical reaction that is difficult to synthesize with typical chemical methods. The global enzyme market size is predicted to expand at a CAGR of 6.5\% from 2021 to 2028. Enzymatic reactions are highly chemo, regio, and stereoselective and produce various fine chemicals such as drugs, agrochemicals, and fragrance molecules. Peroxidases (PO) (EC 1.11.1.x) are a large class of enzymes that play an important role in various biological processes. Chloroperoxidase (CPO, EC 1.1.1.10) is a versatile fungal haem-thiolate protein that is useful in the asymmetric synthesis of chiral building blocks and has an important role in a number of biological processes. CPO{\textquoteright}s main biological role is chlorination, although it also catalyses haem PO, catalase (CAT), and reactions similar to cytochrome P450. However, CPO performs both oxidation and stereo-specific halogenation of chemical molecules. The haem and vanadium POs are produced by Caldariomyces fumago, and Curvularia inaequalis, respectively, and are capable of halogenating the flavanones, naringenin, and hesperetin, at C-6 and C-8 in the presence of either Cl- or Br-. In this review, we discussed the various applications of CPO including synthesis of epoxides, drugs, halogenation of thymol, nitriles, the Aza-Achmatowicz reaction, and biomedical applications such as cancer and biosensors. In light of these novel features, we have provided a detailed review of CPOs and their applications in various stereoselective chemical transformations of industrial relevance.

}, keywords = {active pharmaceutical ingredients, Biotransformation, Caldariomyces fumago, chemo, Chloroperoxidase, regio, stereoselectivity}, issn = {1024-2422}, doi = {10.1080/10242422.2022.2107919}, author = {Bhandari, Yogesh and Sajwan, Hemlata and Pandita, Parul and Koteswara Rao, Vamkudoth} } @article {49015, title = {Ligand-free MnBr2-catalyzed chemo- and stereoselective hydroboration of terminal alkynes}, journal = {Chemistry-an asian jounrnal}, volume = {19}, year = {2024}, month = {MAY}, type = {Article}, abstract = {

Developing simple and benign protocols for synthesizing alkenylboronates is crucial as they are synthetically valuable compounds in various organic transformations. In this work, we report a straightforward ligand-free protocol for synthesizing alkenylboronates via atom-economical hydroboration of alkynes with HBpin catalyzed by a manganese salt. The reaction shows a high level of chemo and regioselectivity for the terminal alkynes and exclusively produces E-selective alkenylboronates. The hydroboration scope is vast, with the resilience of a range of synthetically beneficial functionalities, such as halides, ether, alkenyl, silyl and thiophenyl groups. This reaction proceeds through the involvement of a metal-hydride intermediate. The developed alkenylboronate can be smoothly converted to useful C-C, C-N and C-I bond-forming reactions.

}, keywords = {alkenylboronates, alkyne, Hydroboration, manganese, stereoselectivity}, issn = {1861-4728}, doi = {10.1002/asia.202400158}, author = {Pawar, Rameshwar B. and Karmur, Mital H. and Punji, Benudhar} }