Metal-Free One-Pot Domino Synthesis of Oxazolidinethione Derivatives of Quaternary Amino Acids from α-Amino Esters and Aldehydes Using CS.

We present a streamlined, metal-free, one-pot domino approach to efficiently synthesize oxazolidinethione derivatives containing substituted quaternary amino acids. This method employs α-amino esters, aldehydes, and CS under mild conditions, constructing three new bonds (C-N, C-C, and C-O) to produce oxazolidinethione compounds featuring a quaternary center and a beta-hydroxy derivative in high yields. This scalable protocol enables the creation of libraries of biologically significant, intricate amino acid derivatives using amino esters and aldehydes.

2-Amino-5-methylene-pyrimidine-4,6-dione-based Janus G-C nucleobase as a versatile building block for self-assembly.

This communication reports a nature-inspired Janus G-C nucleobase featuring two recognition sites: DDA (G mimic) and DAA (C mimic), which is capable of forming a linear tape-like supramolecular polymer structure. As demonstrated herein, the amino group of this self-assembling system can be further modified to yield a highly stable quadruple H-bonding system as well as a masked self-assembling system cleavable upon exposure to light.

Unravelling the Nucleophilicity of Butenolides for 1,6-Conjugate Addition to p-Quinone Methides: A Direct Access to Diversely Substituted Butenolide-Derived Diarylmethanes.

A Lewis acid catalyzed regioselective C-C bond is constructed through β-addition of deconjugated butenolides with p-quinone methides in a 1,6-conjugate addition manner. Interestingly, Lewis acid catalyzed vinylogous Mukaiyama-Michael reaction of silyloxyfurans with p-QMs proceeds selectively through the α or γ position exclusively. The reaction is mild with broad substrate scope, thus allowing easy access to a wide range of bis-arylated α-/β-/γ-substituted butenolides.

Iron Catalyzed Hydroformylation of Alkenes under Mild Conditions: Evidence of an Fe(II) Catalyzed Process.

Earth abundant, first row transition metals offer a cheap and sustainable alternative to the rare and precious metals. However, utilization of first row metals in catalysis requires harsh reaction conditions, suffers from limited activity, and fails to tolerate functional groups. Reported here is a highly efficient iron catalyzed hydroformylation of alkenes under mild conditions.

A modular approach towards functionalized highly stable self-complementary quadruple hydrogen bonded systems.

Self-complementary quadruple hydrogen bonded systems have shown potential as key building blocks for developing various supramolecular polymers. Opportunities for the introduction of multiple functionalities would further augment, in principle, their application potential. Herein, we report a novel modular approach to simultaneously introduce two closely aligned side chains into AADD-type self-complementary quadruple hydrogen-bonding systems.

H-Bonding Assisted Self-Assembly of Anionic and Neutral Ligand on Metal: A Comprehensive Strategy To Mimic Ditopic Ligands in Olefin Polymerization.

Self-assembly of two neutral ligands on a metal to mimic bidentate ligand coordination has been frequently encountered in the recent past, but self-assembly of an anionic ligand on a metal template alongside a neutral ligand remains an elusive target. Such a self-assembly is hampered by additional complexity, wherein a highly negatively charged anion can form intermolecular hydrogen bonding with the supramolecular motif, leaving no scope for self-assembly with neutral ligand. Presented here is the self-association of anionic ligand 3-ureidobenzoic acid (2a) and neutral ligand 1-(3-(diphenylphosphanyl)phenyl)urea (1a) on a metal template to yield metal complex [{COOCHNH(CO)NH}{PhPCHNH(CO)NH}PdMeDMSO] (4a).

Coumarin-Appended Stable Fluorescent Self-Complementary Quadruple-Hydrogen-Bonded Molecular Duplexes.

In this paper we report a coumarin-conjugated self-assembling system adorned with valuable features such as high duplex stability and a built-in fluorophore, which would augment its application potential. This system forms a highly stable molecular duplex in a nonpolar solvent (K > 1.9 × 10 M in CDCl).

Expedient Cobalt-Catalyzed C-H Alkynylation of (Enantiopure) Benzylamines.

A unified strategy for cobalt-catalyzed ortho-C-H bond alkynylation of benzylamines is reported. Simple, commercially available CoBr was used as a cobalt source. The developed alkynylation strategy is robust and efficient and has a broad substrate scope including 1°, 2°, and 3° benzylamines.

Gold vs Rhodium Catalysis: Tuning Reactivity through Catalyst Control in the C-H Alkynylation of Isoquinolones.

A site-selective C-4/C-8 alkynylation of isoquinolones catalyzed by gold and rhodium complexes is reported. A broad range of synthetically useful functional groups (-F, -Cl, -Br, -CF3, -OMe, alkyl, etc.) were tolerated, providing an efficient and robust protocol for the synthesis either C-4- or C-8-alkynylated isoquinolones.