Novel ditopic receptors based on the P2N2 diphosphazane ring: synthesis and x-ray structural characterization of cis and trans bis(crown ether) annelated 1,3,2.lambda.5,4.lambda.5-diazadiphosphetidine 2,4-disulfide

New hydrogen-bonding organocatalysts: Chiral cyclophosphazanes and phosphorus amides as catalysts for asymmetric Michael additions

“…5 ). To date 14a is the second [ 37 ] reported crystal structure of a cis -cylcodiphosphazane-2,4-disulfide with aromatic substituents on nitrogen. For all other known structures of this type the configuration is either not specified or trans .…”

The development of a new nitrating agent: the unusual regioselective nitration of diphenylpolyethylene glycols and phenylpolyethylene glycols with (trimethylsilyl) nitrate-BF3OEt2

“…Caled for ^^ ,: C, 49.9; H, 4.82; N, 8.74. Found: C, 50.1; H, 4.92; N, 8.65. l-Methoxy-ll-(2'-nitrophenoxy)-3,6,9-trioxaundecane (17) was prepared through the following two steps starting from tetraethylene glycol.…”

Synthesis of Phosphorus-Containing Macrocycles and Cryptands

“…73 The use of hexamethylphosphoric triamide instead of CeH6P(NMe2)2 in the reaction with triethylene glycol bis(o-aminophenyl) ether followed by addition of sulfur gives 53 (cis and trans isomers) based on the P2N2 diphosphazane ring (Scheme 30). 74 In the course of this reaction the macrocycles 54a,b and the bismacrocycle 55 are isolated. The synthesis of a cyclic bis(diaminodiphenylphosphonium salt) namely the 2,2,7,7-tetraphenyldecahydro-l,3,6,8,2,7-tetraazadiphosphecine-2,7-diium dibromide (56) consists in the successive reactions of chlorodiphenylphosphine with bromine and then with 1,2-ethanediamine (Scheme 31).…”