A reinvestigation of the synthesis of cis-1,2,3,4,4a,10a-hexahydro[1,4]benzodioxino[2,3-c]pyridine and a synthesis of meso-2,3,4,5,5a,11a-hexahydro-1H-[1,4]benzodioxino[2,3-d]azepine

Abstract

Brenzcatechin‐dinatrium (I) reagiert mit dem N‐Benzyl‐3,4‐ dibrompiperidin (II) zu einem Gemisch der tricyclischen Kondensate (IIIa) und (IVa), die zu (IIIb) bzw. (IVb) debenzyliert werden.

Heterogeneous Gold(I)‐Catalyzed Oxidative Ring Expansion of 2‐Alkynyl‐1,2‐Dihydropyridines or ‐Quinolines Towards Functionalized Azepines or Benzazepines

“…A mixture of 2-(diphenylphosphino)ethyltriethoxysilane (0.565 g, 1.5 mmol) and 2.0 g of mesoporous MCM-41 material in 130 mL of dry toluene was stirred at 110°C for 24 h under argon. The solid product was filtered, washed with chloroform (25 mL), and dried under vacuum at 130°C for 5 h. Then dried powdery solid was soaked in a solution of 3.0 g of Me 3 SiCl in 110 mL of dry toluene at room temperature with stirring for 24 h. The white solid product was filtered, washed with acetone (3 × 20 mL), and dried in vacuum at 100°C for 3 h to provide 2.432 g of diphenylphosphine-functionalized MCM-41 material [MCM-41-Ph 2 P]. The phosphine content of MCM-41-Ph 2 P was determined to be 0.44 mmol g À 1 by elemental analysis.…”

“…In view of their significant medicinal and bioactive properties, the synthesis of azepine‐containing heterocycles has attracted considerable interest from chemists and pharmacologists. Traditionally, azepine frameworks could be constructed by intramolecular Claisen‐Schmidt cyclization, condensation reaction, radical addition, Heck coupling, Beckman rearrangement, olefin metathesis, ring‐expansion through nitrogen transfer, and some related cyclo‐processes . However, most of the reported methods require multiple‐step synthesis.…”

Rhodium(I)‐Catalyzed Intermolecular Aza‐[4+3] Cycloaddition of Vinyl Aziridines and Dienes: Atom‐Economical Synthesis of Enantiomerically Enriched Functionalized Azepines

“…[1e] Meanwhile,a zepine derivatives also serve as key building blocks in the synthesis of structurally complex targets,s uch as iboxyphylline and glucosepane. [2] Furthermore,t he synthesis of seven-membered Nheterocycles in an enantioselective manner by catalytic methods is much more challenging and still rare. However,r elative to reactions to construct five-and sixmembered Nheterocycles,t he development of efficient methodologies for the construction of azepine skeletons is often much more difficult because of the unfavorable entropic factors and transannular interactions.…”

“…However,r elative to reactions to construct five-and sixmembered Nheterocycles,t he development of efficient methodologies for the construction of azepine skeletons is often much more difficult because of the unfavorable entropic factors and transannular interactions. [2] Furthermore,t he synthesis of seven-membered Nheterocycles in an enantioselective manner by catalytic methods is much more challenging and still rare. [3] The[ m + n]c ycloaddition has been established as ar eliable and atom-economical method for the synthesis of heterocycles from simple starting materials.…”

A reinvestigation of the synthesis of trans-(±)-1,2,3,4,4a,10a-hexahydro [1,4] benzodioxino[2,3-c]pyridine

“…Recently ( k )-truns-2,3,3a,9a-tetrahydro [ 1,4] benzodioxino-[2,3-c]pyrrole 1 was reported as a potent and selective a2antagonist, the 5-flUOrO analogue 2 (fluparoxan) of which has been considered for use in the treatment of depression and male sexual dysfunction. ' Because of the close similarity between compounds 1 and 3 we were interested in preparing the latter and comparing the pharmacological properties of the two.…”