Enantioselective synthesis of nicotinic receptor probe 7,8-difluoro-1,2,3,4,5,6- hexahydro-1,5-methano-3-benzazocine.

[Structure: see text] The development of a concise enantioselective synthesis of nicotinic alkaloid 1 is presented. The route features the synthesis and use of a "stable" aliphatic triflate 21 in an alkylation step to generate Heck precursor 24 and an enantioselective cyclization to establish a compound with the key [3.2.

An annulative approach to highly substituted indoles: unusual effect of phenolic additives on the success of the arylation of ketone enolates.

A novel palladium-catalyzed arylation of ketone enolates with o-nitrohaloarenes was achieved through the addition of phenol additives. The mild reaction conditions employed allowed for the inclusion of a wide variety of functional groups in both substrates to be tolerated. The products of this reaction were then readily reductively cyclized to give highly substituted indoles in moderate to excellent overall yields.

Consequences of correlated solvation on the structures and reactivities of RLi-diamine complexes: 1,2-addition and alpha-lithiation reactions of imines by TMEDA-solvated n-butyllithium and phenyllithium.

6Li and (13)C NMR spectroscopic studies were carried out on [(6)Li]n-BuLi and [(6)Li]PhLi (RLi) in toluene-d(8) containing the following diamines: N,N,N',N'-tetramethylethylenediamine (TMEDA), N,N,N',N'-tetraethylethylenediamine, 1,2-dipyrrolidinoethane, 1,2-dipiperidinoethane, N,N,N',N'-tetramethylpropanediamine, trans-(R,R)-N,N,N',N'-tetramethylcyclohexanediamine, and (-)-sparteine. Dimers of general structure (RLi)(2)S(2) (S = chelating diamine) are formed in each case. Treatment of RLi with two different diamines (S and S') affords homosolvates (RLi)(2)S(2) and (RLi)(2)S'(2) along with a heterosolvate (RLi)(2)SS'.