Carbenoid-mediated nucleophilic “hydrolysis” of 2-(dichloromethylidene)-1,1,3,3-tetramethylindane with DMSO participation, affording access to one-sidedly overcrowded ketone and bromoalkene descendants^§

• Rudolf Knorr,
• Thomas Menke,
• Johannes Freudenreich and
• Claudio Pires

Beilstein J. Org. Chem. 2014, 10, 307–315, doi:10.3762/bjoc.10.28

• -reducing side-reactions to consume the aryllithium reagents 34a,b to some extent, as delineated below. Therefore, acid 10 was treated with an excess of 34a,b which were generated from aryl bromides, using either 2.5 equivalents thereof together with tert-butyllithium (t-BuLi, five equiv) or four

• equivalents of both aryl bromide and n-BuLi. The preformed sodium carboxylate of 10 in place of 36 was apparently too insoluble in Et2O to react with 34. The primary products 35 tend to eliminate Li2O slowly with formation of ketones 38 in the presence of aryllithium reagents 34 which will rapidly add to 38

• , creating the tertiary alcohols 39. The unwanted side-products 39 might also arise during simple aqueous work-up where hydrolytic ketone formation from primary products such as 35 was often [40][41] able to compete with the fast protolysis of residual aryllithium reagents. To avoid this suspected mischief

Ring-opening reaction of 2,5-dioctyldithieno[2,3-b:3',2'-d]thiophene in the presence of aryllithium reagents

• Hao Zhong,
• Jianwu Shi,
• Jianxun Kang,
• Shaomin Wang,
• Xinming Liu and
• Hua Wang

Beilstein J. Org. Chem. 2013, 9, 767–774, doi:10.3762/bjoc.9.87

• between the structures of aryl groups and the efficiency of ring-opening reactions are discussed. Keywords: aryllithium reagents; 2'-arylthio-3,3'-bithiophene-2-carbaldehyde; dithieno[2,3-b:3',2'-d]thiophene; nucleophilicity; ring-opening reaction; Introduction Due to the promising optical and

• (1) with nine aryllithium reagents and the characterization of the nine corresponding ring-opening products. These studies should facilitate the understanding of the chemical stability of dithieno[2,3-b:3',2'-d]thiophene, which may be of importance in both organic chemistry and materials science

• . Furthermore, we show a novel method for the synthesis of 2'-arylthio-3,3'-bithiophene-2-carbaldehydes based on the ring-opening reaction. Results and Discussion Ring-opening reaction of 2,5-dioctyldithieno[2,3-b:3',2'-d]thiophene in the presence of aryllithium reagents The aryllithium reagents (Ar–Li) were

Inter- and intramolecular enantioselective carbolithiation reactions

• Asier Gómez-SanJuan,
• Nuria Sotomayor and
• Esther Lete

Beilstein J. Org. Chem. 2013, 9, 313–322, doi:10.3762/bjoc.9.36

• enantioselectivity. The addition of TMEDA increases the rate of racemization, resulting in an inversion of diastereoselectivity to obtain 36, albeit in racemic form [44]. The enantioselective cycloisomerization of achiral organolithiums in the presence of a chiral ligand has been reported with aryllithium reagents

Alkoxide-induced ring opening of bicyclic 2-vinylcyclobutanones: A convenient synthesis of 2-vinyl-substituted 3-cycloalkene-1-carboxylic acid esters

• Xiufang Ji,
• Zhiming Li,
• Quanrui Wang and
• Andreas Goeke

Beilstein J. Org. Chem. 2012, 8, 650–657, doi:10.3762/bjoc.8.72

• ketones. The reaction was triggered by an in situ alkylation with alkyl or aryllithium reagents in the presence of catalytic amounts of Li-chelating agents (e.g., Scheme 1) [24]. The configuration of the newly formed double bond in position 6 was diastereoselectively determined by the configuration of the