DNA-cellulose: an economical, fully recyclable and highly effective chiral biomaterial for asymmetric catalysis

similarity_check: This document is Similarity Check deposited related_data: Supplementary Information copyright_licence: The Royal Society of Chemistry has an exclusive publication licence for this journal peer_review_method: Single-blind history: Received 20 December 2014; Accepted 11 January 2015; Accepted Manuscript published 14 January 2015; Advance Article published 23 January 2015; Version of Record published 24 March 2015This research was supported by the Ministe`re de l’Enseignement Supe´rieur et de la Recherche and the Agence Nationale de la Recherche (NCiS; ANR-2010-JCJC-715-1)

Palladium-Catalyzed Asymmetric Allylic Alkylation of 4-Substituted Isoxazolidin-5-ones: Straightforward Access to β2,2 -Amino Acids.

We report here an unprecedented and highly enantioselective palladium-catalyzed allylic alkylation applied to 4-substituted isoxazolidin-5-ones. Ultimately, the process provides a straightforward access to β2,2 -amino acids bearing an all-carbon quaternary stereogenic center in great yields and a high degree of enantioselectivity

A decade of DNA-hybrid catalysis: from innovation to comprehension

crosscheck: This document is CrossCheck deposited identifier: Michael Smietana (ORCID) identifier: Stellios Arseniyadis (ORCID) identifier: Stellios Arseniyadis (ResearcherID) copyright_licence: The Royal Society of Chemistry has an exclusive publication licence for this journal history: Received 22 January 2017; Accepted 23 April 2017; Accepted Manuscript published 25 April 2017; Advance Article published 9 May 2017We would like to thank the Agence Nationale de la Recherche for funding – the NCiS project (ANR-2010-JCJC-715-1) and the D-CYSIV project (ANR-2015-CE29-0021-01

alpha,beta-Unsaturated 2-Acyl-Imidazoles in Asymmetric Biohybrid Catalysis

International audienceα,β‐Unsaturated acylimidazoles have been used in a plethora of enantioselective transformations over the years and have unsurprisingly become privileged building blocks for asymmetric catalysis. Interestingly however, their use in asymmetric biohybrid catalysis as bidentate substrates able to interact with artificial metalloenzymes has only recently emerged, expanding considerably in the last few years. Easy to prepare and to post‐transform, α,β‐unsaturated acylimidazoles appear as leading synthons for the asymmetric construction of C−C and C−O bonds. This Minireview highlights the current and increasing interest of these key building blocks in the context of asymmetric biohybrid catalysis with the aim to stimulate further research into their still unexploited potential. The use of these α,β‐unsaturated acylimidazoles in metal‐catalyzed and organocatalyzed transformations will be covered in a back‐to‐back Minireview by Renata Marcia de Figueiredo, Jean‐Marc Campagne and co‐workers

Sequential Palladium-Catalyzed Allylic Alkylation/retro-Dieckmann Fragmentation Strategy for the Synthesis of α-Substituted Acrylonitriles.

A straightforward synthesis of α-substituted acrylonitriles is described using 4-cyano-3-oxotetrahydro-thiophene (c-THT) as an acrylonitrile surrogate. This unprecedented two-step sequence featuring a palladium-catalyzed allylic alkylation (Pd-AA) and a retro-Dieckmann fragmentation provides a general entry into diversely substituted 1,4-dienes

Visible light-mediated difluoromethylation/cyclization in batch and flow: scalable synthesis of CHF2-containing benzimidazo- and indolo[2,1-a]isoquinolin-6(5H)-ones.

We report here a practical and cost-effective method for the synthesis of CHF2-containing benzimidazo- and indolo[2,1,a]-isoquinolin-6(5H)-ones through a visible light-mediated difluoromethylation/cyclization cascade. The method, which affords functionalized multifused N-heterocyclic scaffolds in moderate to high yields under mild reaction conditions, is also easily scalable using low-cost 3D printed photoflow reactors

Expanding the 'aplysinospin cascade' through DNA-templated [2+2] photocycloaddition

International audienceInspired by the unique ability of nucleic acids to template chemical transformations that are otherwise impossible in solution, we embarked on the generalisation of our DNA-templated [2+2] photo-induced homo- and heterodimerization of aplysinopsins. Our process ensures a straightforward access to cyclobutane containing natural products and analogues thereof. Most importantly, this conceptual biomimetic achievement presents interesting arguments to build a biosynthetic scenario

Chiral, air stable, and reliable Pd(0) precatalysts applicable to asymmetric allylic alkylation chemistry.

Stereoselective carbon-carbon bond formation via palladium-catalyzed asymmetric allylic alkylation is a crucial strategy to access chiral natural products and active pharmaceutical ingredients. However, catalysts based on the privileged Trost and Pfaltz-Helmchen-Williams PHOX ligands often require high loadings, specific preactivation protocols, and excess chiral ligand. This makes these reactions uneconomical, often unreproducible, and thus unsustainable. Here we report several chiral single-component Pd(0) precatalysts that are active and practically-applicable in a variety of asymmetric allylic alkylation reactions. Despite the decades-long history and widespread use of Trost-type ligands, the precatalysts in this work are the only reported examples of stable, isolable Pd(0) complexes with these ligands. Evaluating these precatalysts across nine asymmetric allylic alkylation reactions reveals high reactivity and selectivity at low Pd loading. Importantly, we also report an unprecedented Pd-catalyzed enantioselective allylation of a hydantoin, achieved on gram scale in high yield and enantioselectivity with only 0.2 mol% catalyst

Merging Copper Catalysis with Nitro Allyl and Allyl Sulfone Derivatives: Practical, Straightforward, and Scalable Synthesis of Diversely Functionalized Allyl Boranes

We report here the first example of a copper-catalyzed transformation involving nitro allyl derivatives. This borylation reaction, which exploits the high versatility of the aforementioned precursor, tolerates a variety of functional groups and allows practical, scalable, and highly straightforward access to diversely substituted allylboronic esters in high yields. The method was also extended to allyl sulfones, which provides a very complementary approach, offering additional structural diversity along with improved stereoselectivities. This new reactivity was further exploited to synthesize γ-fluoroallyl boronic esters as well as various synthetically useful building blocks through key post-functionalizations. Both the reaction mechanism and the chemoselectivity were rationalized experimentally and through DFT calculations