On the control of secondary carbanion structure utilising ligand effects during directed metallation

• Andrew E. H. Wheatley,
• Jonathan Clayden,
• Ian H. Hillier,
• Alison Campbell Smith,
• Mark A. Vincent,
• Laurence J. Taylor and
• Joanna Haywood

Beilstein J. Org. Chem. 2012, 8, 50–60, doi:10.3762/bjoc.8.5

• observation of two structure-types for the carbanion in solution is explained theoretically and by NMR spectroscopy in terms of cis and trans isomerism imparted by partial double bond character in the arene–(α-C) bond. Keywords: directed metallation; Lewis base; ligand effects; lithium; secondary carbanion

Asymmetric synthesis of quaternary aryl amino acid derivatives via a three-component aryne coupling reaction

• Elizabeth P. Jones,
• Peter Jones,
• Andrew J. P. White and
• Anthony G. M. Barrett

Beilstein J. Org. Chem. 2011, 7, 1570–1576, doi:10.3762/bjoc.7.185

• . DMG = directed metallation group. BHT = 2,6-di-tert-butyl-4-methylphenol. Proposed mechanism of α-arylation. Proposed extension of the methodology to synthesize quaternary adducts. Formation of α-methyl, α-aryl Schöllkopf adduct. Formation of quaternary adducts. Hydrolysis of quaternary adducts

Enantiospecific synthesis of [2.2]paracyclophane- 4-thiol and derivatives

• Gareth J. Rowlands and
• Richard J. Seacome

Beilstein J. Org. Chem. 2009, 5, No. 9, doi:10.3762/bjoc.5.9

• ]paracyclophane compounds; aryl sulfonylation and the related sulfenylation facilitates the synthesis of sulfonic acids, sulfonamides and protected thiols [24][25][26] whilst directed metallation has allowed the formation of various sulfides [27][28][29][30]. Very few methodologies allow the synthesis of simple