1262985-48-7Relevant academic research and scientific papers
Cobalt-Catalyzed Enantioselective Synthesis of Chiral gem-Bis(boryl)alkanes
Teo, Wei Jie,Ge, Shaozhong
, p. 12935 - 12939 (2018)
We report an asymmetric synthesis of enantioenriched gem-bis(boryl)alkanes in an enantioselective diborylation of 1,1-disubstituted alkenes catalyzed by Co(acac)2/(R)-DM-segphos. A range of activated and unactivated alkenes underwent this asymmetric diborylation in the presence of cyclooctene as a hydrogen acceptor, affording the corresponding gem-bis(boryl)alkanes with high enantioselectivity. The synthetic utility of these chiral organoboronate compounds was demonstrated through several stereospecific derivatizations and the synthesis of sesquiterpene and sesquiterpenoid natural products.
High-activity cobalt catalysts for alkene hydroboration with electronically responsive terpyridine and α-diimine ligands
Palmer, W. Neil,Diao, Tianning,Pappas, Iraklis,Chirik, Paul J.
, p. 622 - 626 (2015)
Cobalt alkyl complexes bearing readily available and redox-active 2,2′:6′,2″-terpyridine and α-diimine ligands have been synthesized, and their electronic structures have been elucidated. In each case, the supporting chelate is reduced to the monoanionic, radical form that is engaged in antiferromagnetic coupling with the cobalt(II) center. Both classes of cobalt alkyls proved to be effective for the isomerization-hydroboration of sterically hindered alkenes. An α-diimine-substituted cobalt allyl complex proved exceptionally active for the reduction of hindered tri-, tetra-, and geminally substituted alkenes, representing one of the most active homogeneous catalysts known for hydroboration. With limonene, formation of an η3-allyl complex with a C-H agostic interaction was identified and accounts for the sluggish reactivity observed with diene substrates. For the terpyridine derivative, unique Markovnikov selectivity with styrene was also observed with HBPin. (Figure Presented).
Highly regio- and enantioselective catalytic asymmetric hydroboration of α-substituted styrenyl derivatives
Mazet, Clement,Gerard, David
supporting information; experimental part, p. 298 - 300 (2011/02/24)
The catalytic asymmetric hydroboration of a variety of 1,1-disubstituted olefins has been achieved with excellent yields, perfect regioselectivity and in some cases, high levels of enantioselectivity using readily accessible iridium catalyst.
