Transition‐Metal‐Catalyzed 1,2‐Carboboration of Alkenes: Strategies, Mechanisms, and Stereocontrol

Abstract

During the past decade, many research groups have described catalytic methods for 1,2-carboboration, allowing access to structurally complex organoboronates from alkenes. Various transition metals, especially copper, palladium, and nickel, have been widely used in these reactions. This review summarizes advances in this field, with a special focus on the catalytic cycles involved in different metal-catalyzed carboboration reactions, as well as the regio-and stereochemical consequences of the underlying mechanisms. 1,2-Carboboration of other unsaturated systems, such as alkynes and allenes, is outside of the scope of this review. Scheme 1. General depiction of catalyst-controlled 1,2-carboboration. In this scheme and throughout the manuscript, nucleophilic reaction partners are drawn in blue, and electrophilic reaction partners are drawn in red. Scheme 4. Cu(I)-catalyzed borylative radical cyclization. Scheme 5. Cu(I)-catalyzed intramolecular carboboration involving an aldol cyclization. Scheme 6. Cu(I)-catalyzed intramolecular acylboration.Review Isr. J. Chem. 2020, 60, 219 -229 Scheme 7. Cu(I)-catalyzed divergent alkylboration of alkenes. Scheme 8. Cu(I)-catalyzed alkene carboboration with aldehydes as the electrophile. Scheme 9. Cu(I)-catalyzed three-component acylboration. Scheme 10. Cu(I)-catalyzed heteroarylboration of 1,3-dienes.

Intermolecular radical carboamination of alkenes

“…Difunctionalization of alkenes by constructing two different vicinal chemical bonds is a valuable synthetic strategy that has gained great interests during the last few decades. [1][2][3][4][5][6][7][8][9][10][11][12] Among the various vicinal difunctionalizations known, alkene carboamination comprising a C-N bond and a C-C bond formation to provide structurally diverse amine derivatives in a straightforward manner is of particular interest. Initial studies on vicinal alkene carboamination focused on aza-Diels-Alder reactions of electron-rich alkenes with conjugated imines.…”

sp3Bis‐Organometallic Reagents via Catalytic 1,1‐Difunctionalization of Unactivated Olefins

“…[6][7][8][9] Herein, we report the realization of this goal with a platform consisting of a siteselective [1,2]-Ni migration via the intermediacy of I facilitated by the stabilization of the neighboring boron atom, thus setting the stage for establishing the 1,1-difunctionalized linkage bearing a versatile bis-organometallic B,B(Si)reagent. [12,13] Our method is distinguished by its excellent chemo-and regioselectivity profile, even in the context of ethylene valorization.…”

Organocatalytic trans Phosphinoboration of Internal Alkynes

“…Classically, organoboron species are prepared through a hydroboration reaction with C−C or C‐heteroatom π‐bonds. However, a recent focus has been on the development of difunctionalization reactions in which the addition of B−X reagents (X=B, N, O, Si, Se or R) affords access to substrates with two functional groups suitable for subsequent transformations. One example that has only recently received limited attention is the phosphinoboration reaction.…”