[3.1.1]Propellane

Abstract

Recent years have witnessed extensive theoretical2 and ex-perimental3 interest in the small propellanes.4 Because of our previous involvement in the area31 and our extensive interest in derivatives of bicyclo[ 1.1.0] butane,5 we were intrigued with the possibility of studying the synthesis and reactions of the [n.l.l]propellanes. Shortly after the initiation of our studies in this area, reports of the synthesis of complex derivatives of the [4.1.1] propellane system appeared.6 Quite recently, the conversion of 1 into 2 has been reported.7 It was this report which prompted us to disclose our results on the synthesis and reactions of the parent hydrocarbon, [3.1.1]propellane (3).

Synthesis and Stereochemical Properties of Chiral Square Complexes of Iron(II)

“…Formation of 7i–k could be explained by heterolytic C(1)–C(2) bond cleavage directed by the carbonyl group at C(2) (Scheme ). Thus, although the CN, COOH and COOMe groups are electron withdrawing, the positive charge at C(1) in iso‐ 6 , 7 and 8 can be partially stabilized by the + M effect exerted by these groups towards a strong electronic demand, as occurs in α‐carbonyl19 and α‐cyano cations 20…”

Electron ionization mass spectral studies of bridgehead‐substituted norbornan‐2‐ones: camphor derivatives

“…Formation of 7i-k could be explained by heterolytic C(1)-C(2) bond cleavage directed by the carbonyl group at C(2) (Scheme 2). Thus, although the CN, COOH and COOMe groups are electron withdrawing, the positive charge at C(1) in iso-6, 7 and 8 can be partially stabilized by the þM effect exerted by these groups towards a strong electronic demand, as occurs in a-carbonyl [19] and a-cyano cations. [20] Path D, a minor process which is only observed in compounds 1d and 1j, k, involves a 1,4-H rearrangement in 7, giving rise to 9, followed by a McLafferty rearrangement with the loss of 2-methylpropanal to give the radical cation 10.…”

Structures, stabilities, and energies of isomerization of some alkyl cyanides and isocyanides and their corresponding α‐cyanocarbonium and α‐isocyanocarbonium ions

“…Experimental results [3] have been interpreted as demonstrating the stabilization effect of a-cyano substitution on carbonium ions. Theoretical evidence [4] was provided by an examination of changes in bond lengths, presumably resulting from increased electron delocalization, and interpreted as evidence of stabilization through resonance hybridization.…”