Non classé

feedproxy.google.com/~r/acs/joceah/~3/Ut0Xeqr306w/acs.joc.0c00796

Authors: Kazuki Hirano†, Takuya Saito†, Yamato Fujihira†, Daniel M. Sedgwick‡, Santos Fustero‡, and Norio Shibata*†?

feedproxy.google.com/~r/acs/joceah/~3/Xgu8hV31-w4/acs.joc.0c00754

Authors: Thondikkal Sulfikarali†, Jayaprakash Ajay†, Cherumuttathu H. Suresh‡, Padinjare V. Bijina‡, and Sabapathi Gokulnath*†

feedproxy.google.com/~r/acs/oprdfk/~3/iwGsYA9SE90/acs.oprd.0c00120

Authors: Marina Y. Raynbird†?, Joanne B. Sampson†, Dan A. Smith†, Sia^n M. Forsyth†, Jonathan D. Moseley*†§, and Andrew S. Wells‡

feedproxy.google.com/~r/acs/joceah/~3/betiboUnKDA/acs.joc.0c00788

Authors: Humair M. Omer, Peng Liu*, and Kay M. Brummond*

feedproxy.google.com/~r/acs/joceah/~3/qSqlxXyZzPg/acs.joc.0c00536

Authors: Antonin Jaillet†?, Christophe Darcel‡, Je´ro^me Bayardon†, Adrien Schlachter§, Christine Salomon†?, Yoann Rousselin†, Pierre Harvey§, and Sylvain Juge´*†

feedproxy.google.com/~r/acs/joceah/~3/nCAg46CGc_4/acs.joc.9b03329

Authors: Ahmed Adeyemi†, Luke R. Odell†, and Mats Larhed*‡

feedproxy.google.com/~r/acs/oprdfk/~3/JqDqtfD6Hh4/acs.oprd.0c00104

Authors: Robert A. Singer, Sebastien Monfette, David J. Bernhardson, Sergei Tcyrulnikov, and Eric C. Hansen*

The Journal of Organic Chemistry: Latest Articles (ACS Publications)
Authors: Manel Estruch-Blasco†, Diego Felipe-Blanco†, Irene Bosque, and Jose C. Gonzalez-Gomez*
feedproxy.google.com/~r/acs/joceah/~3/TDMNz74tpp0/acs.joc.0c00795

onlinelibrary.wiley.com/doi/abs/10.1002/anie.202004485?af=R

Bulk up : A Pd‐catalyzed enantioselective β‐C(sp³)−H functionalization of thioamides has been developed using a chiral phosphoric acid (CPA) as the chiral auxiliary. Mass spectrometry studies and DFT analysis elucidate the role of the bulky CPA and the assistance of the thioamide ligand, which define a robust chiral cavity for achieving a high level of stereocontrol.

Abstract

A hybrid palladium catalyst assembled from a chiral phosphoric acid (CPA) and thioamide enables a highly efficient and enantioselective β‐C(sp³)−H functionalization of thioamides (up to 99 % yield, 97 % ee ). A kinetic resolution of unsymmetrical thioamides by intermolecular C(sp³)−H arylation can be achieved with high s‐factors. Mechanistic investigations have revealed that stereocontrol is achieved by embedding the substrate in a robust chiral cavity defined by the bulky CPA and a neutral thioamide ligand.

Authors: Hua‐Jie Jiang, Xiu‐Mei Zhong, Zi‐Ye Liu, Rui‐Long Geng, Yang‐Yang Li, Yun‐Dong Wu, Xinhao Zhang, Liu‐Zhu Gong

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onlinelibrary.wiley.com/doi/abs/10.1002/anie.202003676?af=R

Peptide synthesis goes green : A water‐compatible 2,7‐disulfo‐9‐fluorenylmethoxycarbonyl (Smoc) protecting group has been developed that enables solid‐phase peptide synthesis under aqueous conditions as well as efficient postsynthetic purification of the peptides. This protecting group is fluorescent both when attached to an N_α atom and when cleaved and so also allows real‐time monitoring of building block coupling

Abstract

The growing interest in synthetic peptides has prompted the development of viable methods for their sustainable production. Currently, large amounts of toxic solvents are required for peptide assembly from protected building blocks, and switching to water as a reaction medium remains a major hurdle in peptide chemistry. We report an aqueous solid‐phase peptide synthesis strategy that is based on a water‐compatible 2,7‐disulfo‐9‐fluorenylmethoxycarbonyl (Smoc) protecting group. This approach enables peptide assembly under aqueous conditions, real‐time monitoring of building block coupling, and efficient postsynthetic purification. The procedure for the synthesis of all natural and several non‐natural Smoc‐protected amino acids is described, as well as the assembly of 22 peptide sequences and the fundamental issues of SPPS, including the protecting group strategy, coupling and cleavage efficiency, stability under aqueous conditions, and crucial side reactions.

Authors: Sascha Knauer, Niklas Koch, Christina Uth, Reinhard Meusinger, Olga Avrutina, Harald Kolmar

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[cite]10.1038/s41557-020-0475-7[/cite]

The Journal of Organic Chemistry: Latest Articles (ACS Publications)
Authors: Henrik Beer†, Jonas Bresien*†, Dirk Michalik†‡, Anne-Kristin Ro¨lke†, Axel Schulz*†‡§, Alexander Villinger†, and Ronald Wustrack†
feedproxy.google.com/~r/acs/joceah/~3/SKxJzcWnx-s/acs.joc.0c00460

feedproxy.google.com/~r/acs/joceah/~3/Bjy_3q6z9vo/acs.joc.0c00813

Authors: Shane M. Hickey†, Samuel O. Nitschke†, Martin J. Sweetman†, Christopher J. Sumby‡, Douglas A. Brooks†, Sally E. Plush†, and Trent D. Ashton*§?

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feedproxy.google.com/~r/acs/joceah/~3/30G7YhLgOAU/acs.joc.0c00910

Authors: Takuro Matsuoka, Shinsuke Inuki*, Takashi Miyagawa, Shinya Oishi, and Hiroaki Ohno*

feedproxy.google.com/~r/acs/oprdfk/~3/MI8ICuCjSMs/acs.oprd.0c00048

Authors: Alessandro Agosti*, Silvia Panzeri, Federico Gassa, Massimo Magnani, Giulia Forni, Marco Quaroni, Lazzaro Feliciani, and Giorgio Bertolini

onlinelibrary.wiley.com/doi/abs/10.1002/anie.202002106?af=R

A variety of N‐methylated peptides were synthesized in high yield without severe racemization via the generation of acyl N‐methylimidazolium cations. Brønsted acids dramatically accelerated the reaction. The developed amidation reaction enabled the synthesis of a bulky peptide in higher yield and shorter reaction time in comparison with conventional amidation reactions. The first total synthesis of pterulamides I–IV was also achieved.

Abstract

The development of a robust amide‐bond formation remains a critical aspect of N‐methylated peptide synthesis. In this study, we synthesized a variety of dipeptides in high yields, without severe racemization, from equivalent amounts of amino acids. Highly reactive N‐methylimidazolium cation species were generated in situ to accelerate the amidation. The key to success was the addition of a strong Brønsted acid. The developed amidation enabled the synthesis of a bulky peptide with a higher yield in a shorter amount of time compared with the results of conventional amidation. In addition, the amidation can be performed by using either a microflow reactor or a conventional flask. The first total synthesis of naturally occurring bulky N‐methylated peptides, pterulamides I–IV, was achieved. Based on experimental results and theoretical calculations, we speculated that a Brønsted acid would accelerate the rate‐limiting generation of acyl imidazolium cations from mixed carbonic anhydrides.

Authors: Yuma Otake, Yusuke Shibata, Yoshihiro Hayashi, Susumu Kawauchi, Hiroyuki Nakamura, Shinichiro Fuse

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