94978-64-0

Upstream product

• 94195-16-1 7,13-dibenzyl-7,13-diaza-1,4,10-trioxacyclopentadecane 
• 36839-55-1 1,2-bis-(2-iodoethoxy)ethane 
• 612-23-7 2-nitrobenzyl chloride 
• 31249-95-3 Kryptofix 21 

Downstream Products

• 105488-59-3 N,N'-bis(2-aminobenzyl)-1,10-diaza-15-crown-5 

Relevant academic research and scientific papers

Cadmium(II) and lead(II) complexes with novel macrocyclic receptors derived from 1,10-diaza-15-crown-5

Two novel macrocycles, N,N'-bis(2-aminobenzyl)-1,10-diaza-15-crown-5 (L1) and a non-symmetric cryptand incorporating a pyridinyl Schiff-base spacer (L3), both derived from 1,10-diaza-15-crown-5, have been shown to act as receptors for lead(II) and cadmium(II) guests. The X-ray crystal structures reveal an anti conformation for the free ligand L1, but a syn arrangement in the lead(II) complex, [PbL1](ClO4)2. The corresponding cryptates of L3 can be prepared by simple transmetallation reactions starting from the barium cryptate, showing the preference of L3 for the heavy metal ions. The lead(II) ion, unlike cadmium(II), has been shown to be capable of acting as a template agent in the synthesis of L3. The X-ray crystal structures of the metal cryprates allow an insight into the influence of the nature of the metal ion guest on the conformation of the macrobicyclic receptor L3; the most significant changes are a different folding of the crown and variations in the distance between the two pivotal nitrogen atoms and the imine nitrogen atoms. The cryptand can thus expand or contract its cavity in order to accommodate the different metal ions.

Syntheses and Binding Properties of Bibracchial Lariat Ethers (BIBLEs): Survey of Synthetic Methods and Cation Selectivities

A new, two-step method for the synthesis of 4,10-diaza-15-crown-5 and 4,13-diaza-18-crown-6 and their N,N'-disubstituted derivatives from bis(secondary amines) and 1,2-bis(2-iodoethoxy)ethane is described.Essentially, the method utilizes the incipient sidearms as nitrogen-protecting groups prior to cyclization.The yields for cyclization are high, ranging from 32percent to 77percent.The N,N'-disubstituted derivatives of 4,10-diaza-15-crown-5 produced by alkylation or acylation (A), acylation followed by reduction (AR), cyclization (C), hydrogenolysis (H), or single-step cyclization (O) have the following sidearms: H (H, 91percent), MeOCH2CH2 (C, 38percent), EtOCOCH2 (A, 62percent), PhCH2 (C,72percent), 2-MeOPh (C, 52percent), 2-furanylmethyl (C, 67percent), and 2-nitrobenzyl (A, 50percent).N,N'-Dibenzyl-4,10-diaza-18-crown-6 was obtained by cyclization in 63percent yield.The N,N'-disubstituted derivatives of 4,13-diaza-18-crown-6 produced with the new method have the following sidearms: H (H, 92percent), CO-Et (A, 100percent), n-propyl (AR, 78percent), n-butyl (C, 77percent), n-hexyl (C, 32percent; A, 50percent; O, 7percent), n-octyl (AR, 45percent), CO-n-heptyl (A, 71percent), n-nonyl (O, 11percent;A, 45percent;AR, 39percent), CO-n-undecyl (A, 87percent), n-tetradecyl (AR, 26percent), CO-n-tridecyl (A, 78percent), n-hexadecyl (A, 25percent), n-octadecyl (AR, 60percent), CO-n-heptadecyl (A, 100percent), allyl (O, 26percent), propargyl (O, 22percent), HOCH2CH2 (O, 28percent), MeOCH2CH2 (C, 43percent; AR, 76percent), HOCOCH2 (hydrolysis, 81percent), EtOCOCH2 (A, 92percent), PhCH2 (O, 29percent;C, 66percent), 2-furanylmethyl (O, 27percent, C, 62percent), 2-hydroxybenzyl (A, 85percent), 2-methoxybenzyl (O, 30percent), 2-cyanobenzyl (A, 95percent), 2-nitrobenzyl (A, 90percent), 3-nitrobenzyl (A, 95percent), and 4-nitrobenzyl (A, 70percent).The new cyclization method is compared with other, previously published cyclization reactions with respect to overall yield and ease of purification.When this new cyclization cannot be used, diaza crown ethers can be prepared by alkylation of 4,10-diaza-15-crown-5 or 4,13-diaza-18-crown-6.The homogeneous equilibrium cation binding constants (log Ks) have been determined in anhydrous methanol solution for many of the compounds described herein with Na+, K+, and Ca+.The cation selectivities are rationalized in terms of polar, structural, and lipophilicity effects.