Copper‐Catalyzed Stereoselective Aminoboration of Bicyclic Alkenes

Abstract

A copper-catalyzed aminoboration of bicyclic alkenes, including oxa- and azabenzonorbornadienes, has been developed. With this method, amine and boron moieties are simultaneously introduced at an olefin with exo selectivity. Subsequent stereospecific transformations of the boryl group can provide oxygen- and nitrogen-rich cyclic molecules with motifs that may be found in natural products or pharmaceutically active compounds. Moreover, a catalytic asymmetric variant of this transformation was realized by using a copper complex with a chiral bisphosphine ligand, namely (R,R)-Ph-BPE.

Copper Hydride Catalyzed Hydroamination of Alkenes and Alkynes

“…This transformation was later generalized to methylenecyclopropanes and bicyclic alkenes. [25] A recent report disclosed that terminal alkene substrates could be converted to either regioisomer of the 1,2-aminoboronate product with high selectivity, depending upon the boron source and catalyst system used. [26] …”

An Umpolung Strategy for the Synthesis of β-Aminoketones via Copper-Catalyzed Electrophilic Amination of Cyclopropanols

“…However, transition metal catalyzed C sp3 -N bond formation at non-activated C sp3 -centers for the syntheses of aliphatic amines are still very limited. Significant advances of C sp3 -H animation reaction and amination of double bonds 6 have been made recently to synthesize aliphatic nitrogen-containing compounds. Our interest in using cyclopropanols and the related systems as useful alkyl cross-coupling partners to form important C sp3 -C sp3 and C sp3 -heteroatom bonds (Figure 1A and 1B) 7 as well as using polysubstituted amines as potential selective adenylyl cyclase 1 inhibitors for treating inflammatory and neuropathic pain 8 prompted us to develop an efficient copper-catalyzed electrophilic amination 9 of cyclopropanols to synthesize various β-aminoketones, 10 which are commonly prepared by the conjugation addition of amine nucleophiles to α,β-unsaturated carbonyls 11 or the Mannich-type reactions between azomethines and enolates.…”

Asymmetric Synthesis of Secondary and Tertiary Boronic Esters

“…[153] Another area of intense research interest in recent years has been the copper-catalysed aminoboration of alkenes.I n 2013, Miura and Hirano reported the copper-catalysed aminoboration of styrene derivatives with B 2 pin 2 and Obenzoyl-N,N-dialkylhydroxylamines,w here the transient borylated alkyl-copper species is proposed to undergo electrophilic amination with the O-benzoylhydroxylamine (Scheme 44). [154] Preliminary studies indicate that good levels of enantioenrichment of the 1,2-aminoborated products can be achieved through the use of chiral diphosphine Duphostype ligands.The methodology was later extended to facilitate the aminoboration of bicyclic alkenes, [155] methylenecyclopropanes, [156] vinylsilanes, [157] and unactivated terminal alkenes. [158] Tortosa has also used this reactivity platform for the aminoboration of cyclopropenes.…”