Synthesis and X-ray crystal structure of a macrocyclic arsa-aza-oxa-cryptand containing eight-membered As4O4 rings

Four-Membered Ring-Containing Spirocycles: Synthetic Strategies and Opportunities

“…Alkylative cyclization reactions of enolates to form cyclobutanes afford entry into this class of spirocycles . In the first of these examples, enolization of 797 in the presence of excess base and 1,3-dibromopropane 798 afforded 799 .…”

Host–Guest Chemistry – p-Block Systems

“…48a Although the mechanism of formation of the host-guest the structural complexity of organic systems. 48 Surprisingly, there have been no investigations of the hostguest behavior of [RPS] n macrocycles, although limited studies of closely related [RAsS] n macrocycles have shown that these function as softer variants of the arsoxanes in their coordination to transition metals. 48 Surprisingly, there have been no investigations of the hostguest behavior of [RPS] n macrocycles, although limited studies of closely related [RAsS] n macrocycles have shown that these function as softer variants of the arsoxanes in their coordination to transition metals.…”

Chemistry of polyfunctional molecules. Part 86. Organoarsenic compounds derived from 1,3-bis(di-iodoarsino)propane with monocyclic, tricyclic, and straight-chain structures; X-ray crystal structure of 2,8,13,14-tetraoxa-1,3,7,9-tetra-arsatricyclo[7.3.1.1]tetradecane

“…1,2-Di-iodo-l,2-diar~acycl0pentane, (3). Sodium sand ( 1.5 g, 65.2 mmol) was added to a quickly stirred solution of 1,3-bis(diiodoarsino)propane (2) (3.30 g, 4.71 mmol) in thf (40 cm3).…”

“…When the tetra-iododiarsine (2) is allowed to react with H,O-NH, in thf [equation (3)], the tricyclic compound (4) is formed. O n recrystallization from methanol-diethyl ether or water, colourless crystals of (4) are obtained.…”

“…This fact is of interest because only a few values for C-H 0 bonds are known at present.I8 Analogous interactions of methylene protons with oxygen atoms of As,O, rings are also found in the spherand [N(CH2CH2)3]s(As,0,),. 3 In order to confirm the CH, OAs interaction in compound (4) its 'H n.m.r. spectrum was simulated.…”