Recent developments in enantioselective organocatalytic cascade reactions for the construction of halogenated ring systems

Author(s):  
Ana Maria Madeira Martins Faisca Phillips ◽  
Ana Maria Madeira Martins Faisca Phillips ◽  
Armando J. L. Pombeiro
2020 ◽  
Vol 74 (1) ◽  
pp. 18-22
Author(s):  
Áron Péter ◽  
David J. Procter

This review focuses on recent developments from our laboratory in the field of radical reactions mediated by the archetypal reductive single electron transfer (SET) reagent, SmI2. Namely, we have expanded the scope of reducible carbonyl moieties to esters and amides and have exploited the resultant ketyl radicals in radical cascade reactions that generate unprecedented scaffolds. Moreover, we have taken the first steps to address the long-standing challenges of catalysis and chiral ligand control associated with the reagent.


Synlett ◽  
2018 ◽  
Vol 30 (02) ◽  
pp. 141-155 ◽  
Author(s):  
Luke Odell ◽  
Mats Larhed ◽  
Linda Åkerbladh

This account summarizes Pd(0)-catalyzed Mo(CO)6-mediated gas-free carbonylative reactions published in the period October 2011 to May 2018. Presented reactions include inter- and intramolecular carbonylations, carbonylative cross-couplings, and carbonylative multicomponent reactions using Mo(CO)6 as a solid source of CO. The presented methodologies were developed mainly for small-scale applications, avoiding the problematic use of gaseous CO in a standard laboratory. In most cases, the reported Mo(CO)6-mediated carbonylations were conducted in sealed vials or by using two-chamber solutions.1 Introduction2 Recent Developments2.1 New CO Sources2.2 Two-Chamber System for ex Situ CO Generation2.3 Multicomponent Carbonylations3 Carbonylations with N and O Nucleophiles4 Carbonylative Cross-Coupling Reactions with Organometallics5 Carbonylative Cascade Reactions6 Carbonylative Cascade, Multistep Reactions7 Summary and Outlook


2018 ◽  
Vol 90 (9) ◽  
pp. 1393-1407 ◽  
Author(s):  
Leonardo Scarabelli

Abstract The field of plasmonics has grown at an incredible pace in the last couple of decades, and the synthesis and self-assembly of anisotropic plasmonic materials remains highly dynamic. The engineering of nanoparticle optical and electronic properties has resulted in important consequences for several scientific fields, including energy, medicine, biosensing, and electronics. However, the full potential of plasmonics has not yet been realized due to crucial challenges that remain in the field. In particular, the development of nanoparticles with new plasmonic properties and surface chemistries could enable the rational design of more complex architectures capable of performing advanced functions, like cascade reactions, energy conversion, or signal transduction. The scope of this short review is to highlight the most recent developments in the synthesis and self-assembly of anisotropic metal nanoparticles, which are capable of bringing forward the next generation of plasmonic materials.


Synthesis ◽  
2017 ◽  
Vol 49 (08) ◽  
pp. 1767-1784 ◽  
Author(s):  
Jean Suffert ◽  
Sarah Blouin ◽  
Gaelle Blond ◽  
Morgan Donnard ◽  
Mihaela Gulea

2021 ◽  
Author(s):  
◽  
Matthew Fisk

<p>The design and development of new chemical reactions is crucial for progress in organic synthesis research. Cascade reactions, involving two or more steps carried out in situ in a single pot, provide a step-efficient and atom-economic route to synthesise polycyclic ring systems. The synthesis of new heterocyclic ring systems provides valuable routes towards complex natural products. Previous work in the Harvey group led to the development of a regioselective palladium-catalysed allylic alkylation (Pd-AA) cascade. This research aims to expand the scope and utility of this existing Pd-AA cascade, by optimising the current reaction conditions and exploring a range of non-symmetric pyran-based bis-electrophiles and nitrogen and sulfur-based β-carbonyl bis-nucleophiles.  Isomeric 2,3-unsaturated silyl glycosides based on D-glucose and D-galactose were successfully synthesised. These substrates were assessed as bis-electrophiles in the Pd-AA cascade. The yield of the cascade was successfully optimised with the glucose-derived substrate 4-hydroxy-6-methylpyran-2-one, using Pd₂(dba)₃ and Xantphos, to 87% from the previously reported 77% yield. However, the galactose-derived silyl glycoside formed an undesired pyranone as the major product. Additionally, a series of β-dicarbonyl compounds (4-hydroxy-6-methylpyran-2-one analogues) were assessed as bis-nucleophiles in the Pd-AA cascade, with all of the analogues forming complex mixtures of side products and a fully unsaturated pyranone as the major isolated product.</p>


Synthesis ◽  
1995 ◽  
Vol 1995 (11) ◽  
pp. 1405-1410 ◽  
Author(s):  
Masataka Ihara ◽  
Takahiko Taniguchi ◽  
Yuji Tokunaga ◽  
Keiichiro Fukumoto

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