Macrocyclic Siloxanes with Two Exocyclic trans-Silanol and Two Exocyclic trans-Amino Functions — Stereoselective Syntheses and Structures

摘要

A simple preparative method for the stereoselective synthesis of ten- and twelve-membered cyclosiloxanes with two exocyclic tluns-silanol and two exocyclic tluns-amino functions has been developed. Thus, treatment of trimethoxy(morpholinomethyl)silane (5) with two molar equivalents of HOPh_2Si-SiPh_2OH and HOPh_2Si-O-SiPh_2OH, respectively, yielded tluns-1,6- bis(2-hydroxy-1 1 1 ,2,2-tetraphenyldisilan-1- yloxy)-l ,6-bis(morpholinomethyl)-3 ,3 ,4 ,4 ,8,8, 9,9-octaphenyl- 2,5,7, 10-tetraoxa-1,3,4,6,8,9-hexqsilacyclodecane (6, 10- membered ring) and tluns-2,8-bis(3-hydroxy-1,l,3,3-tetra-pheny ldisiloxan -1- yloxy ) -2, 8- bis( morpholinomethyl )-4,4,6 , 6, 10, 10, 12, 12-octaphenylcyclohexasiloxane (7, 12-membered ring). In contrast, treatment of 5 with two molar equivalents of HOPh_2C-CPh_2OH afforded (morpholiniomethyl)bis[tetra-phenylethane-1,2-diolato(2-)]silicate (3), a zwitterionic spirocyclic #lambda#~5 Si-silicate. Compounds 3, 6.EtOAc, and 7.PhMe were characterized by elemental analyses (C, H N), solid-state ~(29)Si VACP/MAS NMR studies, solution NMR experiments (~1H, ~(13)C, ~(29)Si; CDCl_3), and crystal structure analyses.