Size Matters: From Two-Dimensional Au -Tl Metallopolymers to Molecular Complexes by Simple Variation of the Steric Demand.

Bis(acetylido) aurates(I) and thallium(I) trifluoromethylsulfonates were used to synthesize Au -Tl metallopolymers, displaying novel and unusual structural motifs of the metal-metal backbones in the solid state: a discrete molecular cluster, 1D chains of interconnected dimers, tetramers, or dodecamers of Au-Tl units, and a 2D-plane network, consisting of alternating edge-linked (AuTl) and (AuTl) cycles. The formation of the different architectures was primarily controlled by the steric demand of the acetylide-substituent groups. Thus, the bulkiest 2,6-diisopropylphenyl derivative yielded a molecular cluster [Tl Au ].

Multicomponent reactions provide key molecules for secret communication.

A convenient and inherently more secure communication channel for encoding messages via specifically designed molecular keys is introduced by combining advanced encryption standard cryptography with molecular steganography. The necessary molecular keys require large structural diversity, thus suggesting the application of multicomponent reactions. Herein, the Ugi four-component reaction of perfluorinated acids is utilized to establish an exemplary database consisting of 130 commercially available components.

A Combined Photochemical and Multicomponent Reaction Approach to Precision Oligomers.

We introduce the convergent synthesis of linear monodisperse sequence-defined oligomers through a unique approach, combining the Passerini three-component reaction (P-3CR) and a Diels-Alder (DA) reaction based on photocaged dienes. A set of oligomers is prepared resting on a Passerini linker unit carrying an isocyano group for chain extension by P-3CR and a maleimide moiety for photoenol conjugation enabling a modular approach for chain growth. Monodisperse oligomers are accessible in a stepwise fashion by switching between both reaction types.

An Update on Isocyanide-Based Multicomponent Reactions in Polymer Science.

Developments and progress in polymer science are often inspired by organic chemistry. In recent years, multicomponent reactions-especially the Passerini and Ugi reactions-have become very important tools for macromolecular design, mainly due to their modular character. In this review, the versatility of the Passerini and Ugi reactions in polymer science is highlighted by discussing recent examples of their use for monomer synthesis, as polymerization techniques, and for postpolymerization modification, as well as their suitability for architecture control, sequence control, and sequence definition.

Recent Progress in the Design of Monodisperse, Sequence-Defined Macromolecules.

This review describes different synthetic strategies towards sequence-defined, monodisperse macromolecules, which are built up by iterative approaches and lead to linear non-natural polymer structures. The review is divided in three parts: solution phase-, solid phase-, and fluorous- and polymer-tethered approaches. Moreover, synthesis procedures leading to conjugated and non-conjugated macromolecules are considered and discussed in the respective sections.

Synthesis of structurally diverse 3,4-dihydropyrimidin-2(1)-ones via sequential Biginelli and Passerini reactions.

The Biginelli reaction was combined with the Passerini reaction for the first time in a sequential multicomponent tandem reaction approach. After evaluation of all possible linker components and a suitable solvent system, highly functionalized dihydropyrimidone-α-acyloxycarboxamide compounds were obtained in good to excellent yields. In a first reaction step, different 3,4-dihydropyrimidin-2(1)-one acids were synthesized, isolated and fully characterized.

High Glass Transition Temperature Renewable Polymers via Biginelli Multicomponent Polymerization.

A novel and straightforward one-pot multicomponent polycondensation method was established in this work. The Biginelli reaction is a versatile multicomponent reaction of an aldehyde, a β-ketoester (acetoacetate) and urea, which can all be obtained from renewable resources, yielding diversely substituted 3,4-dihydropyrimidin-2(1H)-ones (DHMPs). In this study, renewable diacetoacetate monomers with different spacer chain lengths (C3, C6, C10, C20) were prepared via simple transesterification of renewable diols and commercial acetoacetates.