Living Polymerization of Sulfur Ylides. Synthesis of Terminally Functionalized and Telechelic Polymethylene

Abstract

The boron-catalyzed polymerization of dimethylsulfoxonium methylide (1) has been used to prepare telechelic polymethylene polymers. The functional polymers were synthesized by hydroboration of substituted α-olefins. Functional groups including biotin, carbohydrates, primary and secondary amines, and dansyl and pyrene fluorescent groups were tolerant to the reaction conditions. The living polymerization of ylide 1 was initiated and catalyzed by the organoborane. Oxidation of the resulting tris(polymethylene) organoborane produced ω-hydroxy-terminated polymethylenes. The reactions were used to produce α,ω-polymethylenes with molecular weights in the range of 1000−17 000 with polydispersities < 1.1.

C1 polymerization: a unique tool towards polyethylene-based complex macromolecular architectures

“…The molecular weight of these α,ω-difunctionalized PEs ranges from 650 to 20000 g mol -1 and the polydispersity Đ < 1.1. 16,17 Obviously, more functional boranes will lead to more diverse functionalized PEs. Scheme 3 Synthesis of block copolymers by using different macroborane initiators for the polyhomologation of the methylylide Different block copolymers have been successfully synthesized by Shea's group through polymeric borane initiators.…”

A novel synthetic analog of militarin, MA-1 induces mitochondrial dependent apoptosis by ROS generation in human lung cancer cells

“…Selective debenzylation--acetylation of benzyl protecting groups on the primary alcohols, using ZnCl 2 -Ac 2 O-HOAc, followed by deacetylation with K 2 CO 3 in MeOH, gave 2,3,4,5-tetra-Obenzyl-D-mannitol (Lu et al, 2005). Tosylation of the intermediate with TsCl and DMAP in pyridine (Busch et al, 2002), followed by reaction with 4-(tert-octyl)phenol, K 2 CO 3 and KI in CH 3 CN at reflux conditions (Alesso et al, 2003) and debenzylation with Pd/C-HCOOH yielded MA-1 (Robertson and Orrenius, 2000).…”

Polymethylene‐Based Copolymers by Polyhomologation or by Its Combination with Controlled/Living and Living Polymerizations

“…Borane was found to be highly reactive with the vinyl group leading to trifunctional boranes through hydroboration. This method has been employed to obtain functional organoboranes for polyhomologation of ylides affording low polydispersity (PDI < 1.1) α , ω ‐difunctionalized PMs and molecular weight ranging from 650 to 20 000 g mol −1 (Scheme ) …”