Neighbouring Group Participation in N-Methoxymethyl 7-Azanorbornanes 1: The Synthesis of N,N′-Methano-bridged Diazasesquinorbornanes, N³-[3]Polynorbornanes and CN³-[4]Polynorbornanes

Abstract

A new tandem route to N,N'-methano-bridged diazasesquinorbornanes is reported in which 7-azabenzonorbornadienes are reacted with ester-activated N-(methoxymethyl)aziridinocyclobutanes to form adducts which immediately undergo N,N'-methanobridge formation by nucleophilic attack of the nitrogen lone pair of one N-bridge onto the methoxymethyl group attached to the adjacent N-bridge. Alternative routes to N,N'-methano-bridged structures of this type are discussed.

Photolysis of Fused Cyclobutatriazolines: An Adventitious Route to 3,6-Di(2-pyridyl)pyridazonorbornadiene

“…10 The triazoline (18a) was prepared as outlined in Scheme 3, starting from dimethyl tricyclo[4.2.1.0 2,5 ]nona-3,7-diene-3,4-dicarboxylate (Smith's diene) 11 (13a). Reaction of s-tetrazine (8) with (13a) occurred site-specifically at the norbornene π-bond to form the dihydropyridazine (14a), which was converted to the dpp ligand (16a) by dehydrogenation with ddq (15).…”

“…Dimethyl (1α,8α,9β,10α,12α,13β)-11-benzyl-3,6-di(2-pyridyl)-4,5,11-triazapentacyclo[6.5.1.0 2,7 .0 9,13 .0 10,11 ]tetradeca-2,4,6-triene-10, 12-dicarboxylate (19a …”

Dipolar Cycloaddition Reactions of Azomethine Ylides Generated by endocyclic‐exocyclic 1,3‐dipole Rearrangement

“…Advantage of the aza‐ACE coupling over ACE coupling is that it proceeds with complete stereoselectivity towards the syn ‐facial ( exo,exo ‐) products. In addition, aza‐ACE coupling offers flexible choice of substituents on the nitrogen atom including benzyl, phenyl, p ‐nitrobenzyl, p ‐xylyl‐diazide, and methoxymethyl .…”

Reaction of 2,5-bis-trifluoromethyl-1,3,4-oxadiazole with 7-oxanorbornenes revisited: Experimental and quantum-chemical study of reaction stereoselectivity

“…Either Diels-Alder or 1,3-dipolar cycloadditions of small heterocyclic molecules, such as 1,2,4,5-tetrazine [7,8], 1,2,4-triazine [7], 1,3,4-oxadiazole [9,10], phthalazine [11], bis-epoxide [12], or bis-aziridine [13] were used. Using these protocols, a number of functionalized hetero-bridged and polarofacial [n]polynorbornanes was prepared [3,12,14,15]. Amongst heterocyclic 'molecular glues' listed, 2,5-bis-trifluoromethyl-1,3,4-oxadiazole (OD) 1 was recognized as the key reagent for construction of 7-oxabicyclo[2.2.1] moiety at the junction of two norbornene fragments producing COC- [3]polynorbornanes (Scheme 1).…”