Transition Metal‐Catalyzed Dicarbofunctionalization of Unactivated Olefins

Abstract

Transition metal (TM)-catalyzed difunctionalization of unactivated olefins with two carbon-based entities is a powerful method to construct complex molecular architectures rapidly from simple and readily available feedstock chemicals. While dicarbofunctionalization of unactivated olefins has a long history typically with the use of either carbon monoxide to intercept C(sp )-[M] (alkyl-TM) species or substrates lacking in β-hydrogen (β-Hs), development of this class of reaction still remains seriously limited due to complications of β-H elimination arising from the in situ-generated C(sp )-[M] intermediates. Over the years, different approaches have been harnessed to suppress β-H elimination, which have led to the development of various types of olefin dicarbofunctionalization reactions even in substrates that generate C(sp )-[M] intermediates bearing β-Hs with a wide range of electrophiles and nucleophiles. In this review, these developments will be discussed both through the lens of historical perspectives as well as the strategies scrutinized over the years to address the issue of β-H elimination. However, this review article by no means is designed to be exhaustive in the field, and is merely presented to provide the readers an overview of the key reaction developments.

Enantioselective Radical Addition/Cross‐Coupling of Organozinc Reagents, Alkyl Iodides, and Alkenyl Boron Reagents

“…[7,8] If the intermediate radical might instead react with the Ni complex furnishing D,t hen catalyst-based stereocontrol might be realized even though the process involves radical intermediates.T he underlying principles that would enable such ap rocess are aligned with other metal-catalyzed intermolecular dicarbofunctionalizations [9] of alkenes,w hich take place either through carbometalation/cross-coupling [10] pathways or through radical addition/cross-coupling cascades. To address this obstacle,we targeted formation of an eutral a-boryl radical (C,S cheme 1c), which would be more stable and less prone to engage in aS ET-based radical propagation reaction.…”

Facile Preparation of Spirolactones by an Alkoxycarbonyl Radical Cyclization–Cross‐Coupling Cascade

“…[5] Utilizing at hionocarbonate radical precursor, these authors were able to realize a 5-exo radical cyclization/intramolecular arylation of ap endent alkene to give the functionalized g-butyrolactone,f ound in the core of the lignan natural products.D rawing inspiration from approaches such as Sherburns, we sought to develop an alkoxycarbonyl radical 5-exo cyclization-bimolecular crosscoupling cascade that would accomplish an analogously rapid increase in molecular complexity,b ut under the mild conditions offered by photoredox catalysis. [10,11] Moreover,g iven the recent developments in the field of nickel-photoredox dual catalysis, [12][13][14][15] we expected that the carbon-centered radical generated upon cyclization could be intercepted by nickel, allowing for af urther cross-coupling functionalization event to occur.Such atransformation would not only contribute to the burgeoning field of alkene difunctionalization, [16][17][18][19][20] forging two new CÀCb onds in as ingle transformation, but would also allow for rapid and efficient access to functionalized g-butyrolactones. [10,11] Moreover,g iven the recent developments in the field of nickel-photoredox dual catalysis, [12][13][14][15] we expected that the carbon-centered radical generated upon cyclization could be intercepted by nickel, allowing for af urther cross-coupling functionalization event to occur.Such atransformation would not only contribute to the burgeoning field of alkene difunctionalization, [16][17][18][19][20] forging two new CÀCb onds in as ingle transformation, but would also allow for rapid and efficient access to functionalized g-butyrolactones.…”

Direct Carbohydroxylation of Arylalkenes with Allylic Alcohols: Cooperative Catalysis of Copper, Silver, and a Brønsted Acid

“…[1] The development of convenient and efficient methods for the functionalization of olefins is still ar esearch hotspot in organic synthesis although many catalytic methods for the mono-and di-functionalization of olefins have been reported over the past years.Many kind of metals,such as palladium, [2] rhodium, [3] gold, [4] nickel, [5] and copper, [6] were employed as the catalysts for this purpose.Direct carbohydroxylation of alkenes,w hich is the addition of C( alkyl and aryl) and OH to alkenes,i sa n important synthetic method for functionalization of the C=C bond. The catalytic direct carbohydroxylation of arylalkenes with allylic alcohols provided as traightforward and efficient approach for preparing 4,5-unsaturated alcohols.…”

“…[1] The development of convenient and efficient methods for the functionalization of olefins is still ar esearch hotspot in organic synthesis although many catalytic methods for the mono-and di-functionalization of olefins have been reported over the past years.Many kind of metals,such as palladium, [2] rhodium, [3] gold, [4] nickel, [5] and copper, [6] were employed as the catalysts for this purpose. [1] The development of convenient and efficient methods for the functionalization of olefins is still ar esearch hotspot in organic synthesis although many catalytic methods for the mono-and di-functionalization of olefins have been reported over the past years.Many kind of metals,such as palladium, [2] rhodium, [3] gold, [4] nickel, [5] and copper, [6] were employed as the catalysts for this purpose.…”

“…[14] Despite the importance of this type of alcohol, synthetic methodologies to access 4,5unsaturated alcohols are very limited and either suffer from low yield or do not meet the requirements of green chemistry. Thecopper catalyst was first screened in the presence of triphenylphosphine (PPh 3 ), AgSbF 6 ,a nd 4-nitrobenzoic acid BzOH) as the ligand, Lewis acid catalyst, and Brønsted acid catalyst, respectively,in1,4-dioxane containing 10 equivalents of water (H 2 O) at 100 8 8C(entries [1][2][3][4][5][6]. Thecopper catalyst was first screened in the presence of triphenylphosphine (PPh 3 ), AgSbF 6 ,a nd 4-nitrobenzoic acid BzOH) as the ligand, Lewis acid catalyst, and Brønsted acid catalyst, respectively,in1,4-dioxane containing 10 equivalents of water (H 2 O) at 100 8 8C(entries [1][2][3][4][5][6].…”