Copper-Catalyzed Heteroarylboration of 1,3-Dienes with 3-Bromopyridines: A cine Substitution

Stereoselective synthesis of all-cis boryl tetrahydroquinolines via copper-catalyzed regioselective addition/cyclization of o-aldiminyl cinnamate with B2Pin2

A copper catalyzed intramolecular 1,2-carboboration of o-aldiminyl cinnamate has been realized in both regio- and stereoselective fashions. This reaction provides a convenient entry to highly valuable and otherwise challenging cis-2,3,4-trisubstituted tetrahydroquinolines carrying a 4-boryl group. An unusual non-Michael addition intermediate or alternatively, a cyclic enolate is proposed to account for the intriguing all-cis configuration in the final products.

Organoboron chemistry comes to light: recent advances in photoinduced synthetic approaches to organoboron compounds

Photoinduced synthetic approaches to organoboron compounds have attracted significant attention in the recent years. Photochemical activation of organic molecules enables generation of reactive intermediates from a variety of precursors, resulting in borylation methods with improved and broader substrate scopes. The review summarizes recent developments in the area of photoinduced reactions of organoboron compounds with an emphasis on borylation of haloarenes, amine derivatives, and redox-active esters of carboxylic acids, as well as photoinduced rearrangements of organoboron compounds and photoinduced synthesis of organoboron compounds from alkenes and alkynes.

Cu-Catalyzed highly selective reductive functionalization of 1,3-diene using H2O as a stoichiometric hydrogen atom donor

A copper-catalyzed highly regio- and diastereo-selective reductive reaction of terminal 1,3-diene with water and aldehyde has been developed. This chemistry afforded a product containing a terminal alkenyl group, which is a versatile kind of precursor for organic synthesis, with the scope for various substrates. The present reaction system could realize the catalytic transfer of hydrogen to diene using water as a stoichiometric H atom donor. In this transformation, B2Pin2, a mild and practical kind of reductant was used as the mediator. The reaction pathway of this practical strategy was illustrated by a control experiment.

Copper-Catalyzed Regioselective and Diastereoselective Synthesis of Borylated 1-Benzo[ b]azepines

A practical regioselective and diastereoselective synthesis of functionalized 1-benzo[ b]azepines by copper-catalyzed intramolecular cyclization has been developed. The reaction involves borylcupration of a mixture of ( E/ Z)-1,3-dienes, followed by capture of the generated ( Z)-allylcopper species with an imine to produce 7-membered N-heterocycles as single diastereomers. The reaction is applicable to various ( E/ Z)-dienyl arenes with an imine moiety at the ortho-position, including aryl, alkyl, and heterocyclic aldimines, and ketimines, affording borylated 2,3- cis-substituted 1-benzo[ b]azepines in good yields.

Copper-boryl mediated organic synthesis

Organoboron compounds are valuable synthetic intermediates that find application in a diverse variety of processes including both C-X and C-C bond-forming transformations. This has been achieved by using a variety of boron derivatives. Of these, boronate esters are probably the most versatile and, reflecting this, methods for the generation of boronate esters are of considerable current interest. Given the mild reaction conditions, good functional group tolerance, and low cost of the metal catalyst, the use of copper-boryl reagents is particularly attractive. In this review, methodologies in copper-boryl chemistry are discussed and the many different transformations possible are surveyed.

Cu-catalyzed regioselective borylcyanation of 1,3-dienes

Catalytic regioselective generation of an allyl–Cu complex through Cu–B(pin) (pin = pinacolato) addition to 1,3-dienes followed by reaction with an electrophilic cyanation reagent to afford multifunctional organoboron compounds is presented.