The Power of Iron Catalysis in Diazo Chemistry

The use of iron catalysis to enable reactions with diazo compounds has emerged as a valuable tool to forge carbon–carbon or carbon–heteroatom bonds. While diazo compounds are often encountered with toxic and expensive metal catalysts, such as Rh, Ru, Pd, Ir, and Cu, a resurgence of Fe catalysis has been observed. This short review will showcase and highlight the recent advances in iron-mediated reactions of diazo compounds.1 Introduction2 Insertion Reactions2.1 Insertion into B–H Bonds2.2 Insertion into Si–H Bonds2.3 Insertion into N–H Bonds2.4 Insertion into S–H bonds3 Ylide Formation and Subsequent Reactions3.1 Doyle–Kirmse Rearrangement3.2 [1,2]-Stevens and Sommelet–Hauser Rearrangements3.3 Olefination Reactions3.4 Cycloaddition Reactions3.5 gem-Difluoroalkenylation4 Three-Component Reactions5 Miscellaneous6 Conclusion

Post-Polymerization Modification of Ring Opening Metathesis Polymerization (ROMP)-Derived Materials Using Wittig Reactions

This communication describes our recent efforts to utilize Wittig olefination reactions for the post-polymerization modification of polynorbornene derivatives prepared through ring opening metathesis polymerization (ROMP). Polymerizing α-bromo ester-containing norbornenes provides polymers that can undergo facile substitution with triphenylphosphine. The resulting polymeric phosphonium salt is then deprotonated to form an ylide that undergoes reaction with various aryl aldehydes in a one-pot fashion to yield the respective cinnamates. These materials can undergo further modification through photo-induced [2 + 2] cycloaddition cross-linking reactions.

Pd-Catalyzed sequential hydroarylation and olefination reactions of 3-allylchromones

In this paper, a novel approach to regioselective α- or γ-hydroarylation of 3-allylchromones with electron-rich arenes has been presented.

Palladium-catalyzed aerobic regio- and stereo-selective olefination reactions of phenols and acrylatesviadirect dehydrogenative C(sp2)–O cross-coupling

An efficient olefination protocol for the oxidative dehydrogenation of phenols and acrylates has been achieved using a palladium catalyst and O2as the sole oxidant.

Borata-Wittig olefination reactions of ketones, carboxylic esters and amides with bis(pentafluorophenyl)borata-alkene reagents

Borata-alkenes containing the B(C6F5)2 unit are employed in borata-Wittig olefination reactions.

Ru(ii)/PEG-400 as a highly efficient and recyclable catalytic media for annulation and olefination reactions via C–H bond activation

In this report synthesis of isoquinolinones, isocoumarins, and N-methyl isoquinolinones and olefination of Weinreb amides by C–H bond activation using Ru(ii)/PEG-400 as green and recyclable media are documented.