7-Substituted Norbornadienes¹

Abstract

Several 7-norbomadienyl derivatives have been synthesized utilizing the reaction of norbornadiene and t-butyl perbenzoate. In addition, an<i-7-norbornenol and 7-norborneol have been synthesized by a new and shorter route. The possibility of anchimerically assisted hydrogen abstraction from norbornadiene to give an intermediate homoallylic, nonclassical radical is discussed.

Ruthenium(II)‐Catalyzed [2+2] Cycloadditions of anti 7‐Substituted Norbornenes

“…The synthesis of our required substrates was, for the most part, possible through the application of known protocols from the literature. [14] It was found that starting from commercially available NBD 1a allowed access to the desired substrates as shown in Scheme 1. The synthesis of these materials proceeded smoothly in most cases.…”

“…The solvents were purified by distillation under dry nitrogen, from CaH 2 (Et 3 N) and from potassium/benzophenone (THF). The 7-substituted norbornadienes 1b-c, [14] Cp*RuCl(COD) [21] and the alkyne 4 [22] were prepared according to literature procedures.…”

“…Norbornadiene 1b [14] (0.427 g, 2.60 mmol) in THF (1.0 mL) was transferred at 0°C by a cannula to the reaction mixture. The reaction was stirred at 0°C for 5 min and then warmed to room temp.…”

Terminal, Anionic Carbide, Nitride, and Phosphide Transition‐Metal Complexes as Synthetic Entries to Low‐Coordinate Phosphorus Derivatives

“…[4] A one-pot synthesis has been developed for a high-yield conversion of [Mo(NtBuAr) 3 ] into its methylidyne counterpart (Scheme 2). [5] In this methine (CH) transfer reaction, 7-chloronorbornadiene [25][26][27] is used as the methine source, while the three-coordinate titanium(iii) complex [Ti(NtBuAr) 3 ] is used as a specific chlorine-atom abstractor. It is well documented that [Ti(NtBuAr) 3 ] is potent for the one-electron reduction of metal oxo groups, [28,29] carbonyl groups, [30] metalhalogen bonds, [31] and carbon-halogen bonds.…”

Synthetic Access to the Chlorocyclopentane Cores of the Proposed Original and Revised Structures of Palau′amine

“…This process again capitalizes on the Curtin-Hammett energy profile of the system, only this time in the opposite direction to advance 10 through sigmatropic rearrangement and reduction. The hydroxy group in 20 underwent substitution with chloride resulting in net retention of configuration at C17, presumably as a result of π-bond anchimeric assistance, [37] to afford the chloride 21 (97% yield, over 2 steps), which constitutes the C17 epimer of 14 (see Scheme 4).…”