Iron catalysts with N-ligands for carbene transfer of diazo reagents

Abstract

This review provides an overview of the catalytic activity of iron complexes of nitrogen ligands in driving carbene transfers towards CC, C–H and X–H bonds. The reactivity of diazo reagents is discussed as well as the proposed reaction mechanisms.

The Power of Iron Catalysis in Diazo Chemistry

“…A metal carbene can then be used for a wide variety of reactions, notably cyclopropanation and insertion reactions. [7][8][9][10][11][12][13][14] Since their initial discovery until the present day, diazo compounds have been the subject of constant research where numerous advancements have been made in this field. The most commonly employed transition metal catalysts with diazo compounds are Rh and Cu, which have been highly efficient in mediating carbene reactions with high selectivities and at low loadings.…”

“…The most commonly employed transition metal catalysts with diazo compounds are Rh and Cu, which have been highly efficient in mediating carbene reactions with high selectivities and at low loadings. [7][8][9][10][11][12][13]15 However, these precious and toxic metals have shown equal, if not less, efficiency compared to iron catalysts in certain transformations with diazo compounds. The first iron-catalyzed reaction with diazo compounds was reported in 1994 for the cyclopropanation of olefins.…”

“…Iron-catalyzed C-H insertion and cyclopropanation reactions are well known and described as main routes for C-H functionalization with many key developments in the field over the past decade. [10][11][12][13][14] Insertion reactions into C-H bonds catalyzed by iron complexes are highly appreciated for their efficiency, selectivity, and sustainability when compared to alternative methods to functionalize activated and non-activated C-H bonds. 12 In addition, cyclopropanation reactions of diazo compounds have been significantly studied using iron catalysts as better alternatives to precious metal catalysts.…”

“…12 In addition, cyclopropanation reactions of diazo compounds have been significantly studied using iron catalysts as better alternatives to precious metal catalysts. 11 As a result, several reviews have comprehensively reported differ-ent aspects in the field, whereas iron-catalyzed cyclopropanation and C-H functionalization have been recently covered in different publications. 3,4,[10][11][12][13] Thus, to avoid repetition with recent reviews on the topic, this short review will only highlight recent developments in iron-catalyzed transformations with diazo compounds that have been reported since 2014 while excluding C-H insertion and cyclopropanation reactions.…”

Achieving selectivity in porphyrin bromination through a DoE-driven optimization under continuous flow conditions

“…Porphyrins and related compounds are a class of macrocycles that play a leading role in catalysis, [1][2][3] molecular recognition, [4][5][6] energy conversion [7] and photomedicine. [8,9] Their remarkable optical and electrochemical properties can be modulated by a careful choice of peripheral substituents or by metalation of the inner core.…”