- Asymmetric synthesis of 1-heteroaryl-1-arylalkyl tertiary alcohols and 1-pyridyl-1-arylethanes by lithiation-borylation methodology
-
The synthesis of highly enantioenriched α-heterocyclic tertiary alcohols has been achieved via lithiation-borylation of a configurationally stable lithiated carbamate and heterocyclic pinacol boronic esters followed by oxidation. Protodeboronation of the α-heterocyclic tertiary boronic esters using TBAF·3H2O or CsF gave highly enantioenriched 1-pyridyl-1-arylethanes in high er.
- Watson, Charlotte G.,Aggarwal, Varinder K.
-
supporting information
p. 1346 - 1349
(2013/05/09)
-
- Synthesis of novel halopyridinylboronic acids and esters. Part 2: 2,4, or 5-Halopyridin-3-yl-boronic acids and esters
-
This paper describes a general method for the synthesis and the isolation of novel 2,4, or 5-halopyridin-3-yl-boronic acids and esters 4, 7, 10, 13, 15. These compounds are prepared taking into account a regioselective halogen-metal exchange using nBuLi or a regioselective ortho-lithiation using lithium diisopropylamide and subsequent quenching with triisopropylborate starting from appropriate mono or dihalopyridines. All substrates studied to date provided a single regioisomeric boronic acid or ester product. Additionally, these compounds have been found to undergo Pb-catalyzed coupling with a range of arylhalides and authorize a strategy to produce new pyridines libraries.
- Bouillon, Alexandre,Lancelot, Jean-Charles,Collot, Valerie,Bovy, Philippe R.,Rault, Sylvain
-
p. 3323 - 3328
(2007/10/03)
-