Organocatalyzed Group Transfer Polymerization

Abstract

In contrast to the conventional group transfer polymerization (GTP) using a catalyst of either an anionic nucleophile or a transition-metal compound, the organocatalyzed GTP has to a great extent improved the living characteristics of the polymerization from the viewpoints of synthesizing structurally well-defined acrylic polymers and constructing defect-free polymer architectures. In this article, we describe the organocatalyzed GTP from a relatively personal perspective to provide our colleagues with a perspicuous and systematic overview on its recent progress as well as a reply to the curiosity of how excellently the organocatalysts have performed in this field. The stated perspectives of this review mainly cover five aspects, in terms of the assessment of the livingness of the polymerization, limit and scope of applicable monomers, mechanistic studies, control of the polymer structure, and a new GTP methodology involving the use of tris(pentafluorophenyl)borane and hydrosilane.

Organocatalyzed Group Transfer Polymerization of Alkyl Sorbate: Polymer Synthesis, Postpolymerization Modification, and Thermal Properties

“…However, the GTP method has been much more advantageous in experimental operations than anionic polymerization for its much less strict condition requirements. The recent application of organocatalysts has significantly improved the conventional GTP method in aspects of the catalytic activity, applicable monomers, livingness of polymerization, and control of polymer architecture. − As the same, we also expect that it can help to improve the diastereoselective and stereoregular control for the polymerization of conjugated polar diene monomers. In this study, we report (1) the organocatalytic GTPs of ethyl, n -hexyl, and n -octadecyl sorbates using superbase ( t -Bu-P 4 ) and strong Lewis acid (Me 3 SiNTf 2 ), (2) the chemical modification, diastereochemistry, and stereoregularity of the obtained polymers, and (3) the thermal properties of the poly­(alkyl sorbate)­s and their modified polymer products, as shown in Scheme .…”

100th Anniversary of Macromolecular Science Viewpoint: Polymerization of Cumulated Bonds: Isocyanates, Allenes, and Ketenes as Monomers

“…Many advances have been made in controlled chain growth polymerization techniques of radical polymerization (RP), ring opening polymerization (ROP), and ring opening metathesis polymerization (ROMP) . Less common controlled polymerization techniques include group transfer polymerization (GTP) and Grignard metathesis polymerization (GRIM). − In RP, common monomers are terminal carbon–carbon double bonds that produce hydrocarbon backbone with substituents on every other carbon atom. Alternatively, in ROP, common monomers are cyclic molecules containing one or more polar bonds, such as an ester or ether, that produce a linear polymer backbone that has the same functionality (i.e., cyclic ester produces a linear polyester).…”

Poly(β‐trimethylsilyloxy ester): A Degradable Polymer Based on Retro Mukaiyama Aldol Reaction

“…[18][19][20][21] In addition, recent advances in superbases demonstrate that they have not only high Brønsted basicity but also silicon activation ability, which leads to catalyze the well-known Mukaiyama aldol and related organic reactions, [22][23][24][25][26][27][28] and also polymerization reactions, for example, anionic [29][30] and group transfer polymerizations. [31,32] In this study, we pay our attention to the Mukaiyama aldol polyaddition using organic superbases as the catalysts, and for the first time report the highly sterically hindered phosphazene superbase, t-Bu-P 4 , catalyzed Mukaiyama aldol polyaddition between a bis(silyl ketene acetal) (MTS 2 ) and three dialdehydes, as shown in Scheme 1, and the degradation properties of the resulting poly(𝛽-trimethylsilyloxy ester)s based on the retro Mukaiyama aldol reaction mechanism. Scheme 1 also makes a clear comparison between the reported Lewis acid catalyzed Mukaiyama al- M n,SEC a) [g mol −1 ] M w /M n a)…”