Manganese(iii)-mediated radical cyclisations for the (Z)-selective synthesis of exo-alkylidene pyrrolidinones and pyrrolidines

As the enzyme toolbox for biocatalysis has expanded, so has the potential for the construction of powerful enzymatic cascades for efficient and selective synthesis of target molecules. Additionally, recent advances in computer-aided synthesis planning (CASP) are revolutionizing synthesis design in both synthetic biology and organic chemistry. However, the potential for biocatalysis is not well captured by tools currently available in either field. Here we present RetroBioCat, an intuitive and accessible tool for computer-aided design of biocatalytic cascades, freely available at retrobiocat.com. Our approach uses a set of expertly encoded reaction rules encompassing the enzyme toolbox for biocatalysis, and a system for identifying literature precedent for enzymes with the correct substrate specificity where this is available. Applying these rules for automated biocatalytic retrosynthesis, we show our tool to be capable of identifying promising biocatalytic pathways to target molecules, validated using a test-set of recent cascades described in the literature.

Download Full-text

Enantioselective Synthesis of Azamerone

10.26434/chemrxiv.7369844.v1 ◽

2018 ◽

Author(s):

Matthew L. Landry ◽

Grace McKenna ◽

Noah Burns

Keyword(s):

Late Stage ◽

Cross Coupling ◽

Enantioselective Synthesis ◽

Selective Synthesis

A concise and selective synthesis of the dichlorinated meroterpenoid azamerone is described. The paucity of tactics for the synthesis of chiral organochlorides motivated the development of unique strategies for accessing these motifs in enantioenriched forms. The route features a novel enantioselective chloroetherification reaction, a Pd-catalyzed cross-coupling between a quinone diazide and a boronic hemiester, and a late-stage tetrazine [4+2]-cycloaddition/oxidation cascade.

Download Full-text

Enantioselective Synthesis of Azamerone

10.26434/chemrxiv.7369844 ◽

2018 ◽

Author(s):

Matthew L. Landry ◽

Grace McKenna ◽

Noah Burns

Keyword(s):

Late Stage ◽

Cross Coupling ◽

Enantioselective Synthesis ◽

Selective Synthesis

A concise and selective synthesis of the dichlorinated meroterpenoid azamerone is described. The paucity of tactics for the synthesis of chiral organochlorides motivated the development of unique strategies for accessing these motifs in enantioenriched forms. The route features a novel enantioselective chloroetherification reaction, a Pd-catalyzed cross-coupling between a quinone diazide and a boronic hemiester, and a late-stage tetrazine [4+2]-cycloaddition/oxidation cascade.

Download Full-text

Selective α,α-Dibromination of Arylethanones with Copper(II) Bromide

Letters in Organic Chemistry ◽

10.2174/1570178616666190118152325 ◽

2019 ◽

Vol 16 (9) ◽

pp. 700-704

Author(s):

Jitander K. Kapoor ◽

Loveena Arora ◽

Om Prakash

Keyword(s):

Ethyl Acetate ◽

Heterogeneous System ◽

Side Chain ◽

Selective Synthesis ◽

Aromatic Ketones

Various arylethanones including electron-rich aromatic ketones such as o-hydroxyacetophenone and its p-isomer underwent selective side-chain α,α-dibromination using a heterogeneous system consisting of four molar equivalents of copper(II) bromide in chloroform-ethyl acetate under reflux. This study provides the cleanest method for the selective synthesis of several synthetically useful α,α-dibromoketones which are otherwise difficult to prepare.

Download Full-text