Organoboronic acids reactions with

Nitroalkenes are good candidates for the rhodium-catalyzed asymmetric 1,4-addition of organoboronic acids. Hayashi et al. reported that the reaction of 1-nitrocyclohexene with phenylboronic acid in the presence of rhodium/ -BINAP catalyst gave 99% ee of 2-phenyl-1-nitrocyclohexane (Scheme 38).117... 

The reaction mechanism proposed for the addition of organostannanes [29] is similar to that for organoboronic acids. An example of the reaction of methyl vinyl ketone 42 is outlined in Scheme 3.15. The catalytic cycle involves a cationic rhodium complex G, phenylrhodium H, and oxa-n -allylrhodium I. Stannyl enol ether 44 is formed by the reaction of oxa-n -allylrhodium I with Me3SnBF4, which upon hydrolysis gives the ketone 43. The lower yields in the absence of water were explained by the further reaction of 44 with methyl vinyl ketone 42. The rapid hydrolysis with water may prevent such oligomerization. 

Suzuki reaction A palladium catalyzed reaction that results in the formation of new carbon to carbon bonds by reacting an organohalide or organotriflate with an organoboronic acid. 

Aliphatic amines can be readily oxidized by Pd(II) to imines or iminium salts and hydrido complexes. The latter can transfer hydrogen to alkenes, leading to the formation of alkanes as byproducts of the Heck reaction (last example, Scheme 8.18). Such reactions can be avoided by using alkali carbonates as base instead of aliphatic amines [148]. Treatment of stannanes or organoboron derivatives with electron-deficient alkenes under acidic reaction conditions can also lead to formal products of Michael addition instead of the products of a Heck-type reaction [149, 150] (Scheme8.19). 

Tempesti et al. (238) used organoboronic acids (lib) for the immobilization of Mo(VI). It is assumed that the interaction of Mo occurs through a condensation with the supported acid. Reactions reported with the bimetallic material showed an activity and selectivity comparable to those of homogeneous bimetallic analogs. In a comparable approach, Mo was anchored to immobilized phosphorus-containing acids, for example, of cellulose phosphate (11c) (239) or phosphonate resins (11a) (240). 

A. R. Martin, Y. Yang, Palladium Catalyzed Cross-Coupling Reactions of Organoboronic Acids with Organic Electrophiles "Acta Chem. Scand. 1993, 47, 221-230. 

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