Premium
Single diastereomers of unsymmetrical tris‐spirocyclic cyclotriphosphazenes based on 1,1′‐bi‐2‐naphthol—Synthesis and structures
Author(s) -
Bhuvan Kumar N. N.,
Kumara Swamy K. C.
Publication year - 2008
Publication title -
chirality
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.43
H-Index - 77
eISSN - 1520-636X
pISSN - 0899-0042
DOI - 10.1002/chir.20528
Subject(s) - chemistry , diastereomer , stereochemistry , tris , solid state , chirality (physics) , medicinal chemistry , crystallography , chiral symmetry , biochemistry , physics , quantum mechanics , nambu–jona lasinio model , quark
Diastereoselective synthesis and characterization of chiral unsymmetrical tris‐spirocyclic cyclotriphosphazenes based on chiral 1,1′‐bi‐2‐naphthol (BINOL) are reported. Specifically, the chiral compounds (−)N 3 P 3 [1,1′‐O 2 (C 10 H 6 ) 2 ](O‐2,2′C 6 H 4 ‐C 6 H 4 O)Cl 2 [(−)‐ 4 ] and (−)N 3 P 3 [1,1′‐O 2 (C 10 H 6 ) 2 ](OCH 2 CH 2 NMe) 2 [(−)‐ 5 ] are prepared by starting with the chiral mono‐spiro compound (−)N 3 P 3 [1,1′‐O 2 (C 10 H 6 ) 2 ]Cl 4 [(−)‐ 3 ]. Synthesis of four other chiral spirocyclics, N 3 P 3 [1,1′‐O 2 (C 10 H 6 ) 2 ](OCH 2 CH 2 NMe)(O‐2,2′C 6 H 4 ‐C 6 H 4 O)[(−)‐ 6 and (+)‐ 6 ], N 3 P 3 [1,1′‐O 2 (C 10 H 6 ) 2 ](NMe 2 ) 4 [(−)‐ 7 ], N 3 P 3 [1,1′‐O 2 (C 10 H 6 ) 2 ](O‐2,2′C 6 H 4 ‐C 6 H 4 O)(NMeCH 2 CH 2 OH) 2 [(−)‐ 8 and (+)‐ 8 ], and N 3 P 3 [1,1′‐O 2 (C 10 H 6 ) 2 ](O‐2,2′C 6 H 4 ‐C 6 H 4 O)[NHCH 2 CH 2 CH 2 Si(OEt) 3 ] 2 ( 9 ) is also reported herein. Compounds 4 – 6 are obtained in the solid state diastereoselectively and their X‐ray structures have been determined and discussed. The diastereoselectivity is also shown by structural characterization of two distinct isomers in the case of 6 [(−)‐ 6 and (+)‐ 6 , respectively] by starting with precursor of 3 having ( R ) or ( S )‐BINOL residue. The 1 H NMR spectra of 7 and 8 exhibit doublets with virtual coupling for the methyl protons, consistent with the chiral nature of the binaphthoxy residue. The potential of 9 , which hydrolyzes readily in CDCl 3 solution, as a useful precursor for chiral polymer applications is highlighted. Chirality, 2008. © 2008 Wiley‐Liss, Inc.