Self‐Replication and Amplification of Enantiomeric Excess of Chiral Multifunctionalized Large Molecules by Asymmetric Autocatalysis

Self‐replication of large chiral molecular architectures is one of the great challenges and interests in synthetic, systems, and prebiotic chemistry. Described herein is a new chemical system in which large chiral multifunctionalized molecules possess asymmetric autocatalytic self‐replicating and self‐improving abilities, that is, improvement of their enantioenrichment in addition to the diastereomeric ratio. The large chiral multifunctionalized molecules catalyze the production of themselves with the same structure, including the chirality of newly formed asymmetric carbon atoms, in the reaction of the corresponding achiral aldehydes and reagent. The chirality of the large multifunctionalized molecules controlled the enantioselectivity of the reaction in a highly selective manner to construct multiple asymmetric stereogenic centers in a single reaction.     

A tuneable method for N-debenzylation of benzylamino alcohols

[reactions: see text] N-Iodosuccinimide provides a mild, convenient, and tuneable reagent for the selective mono- or didebenzylation in representative, multifunctionalized carbohydrate and amino acid derived N-dibenzylamines with neighboring O-functionality.     

Synthetic method for multifunctionalized oligoarenes using pinacol esters of hydroxyphenylboronic acids

A synthetic method for multifunctionalized oligoarenes using rapid Suzuki-Miyaura coupling of pinacol esters of hydroxyphenylboronic acids and subsequent triflation of the hydroxy group was developed.     

A two-step reaction sequence for the syntheses of tetrahydronaphthalenes

[Reaction: see text] A cobalt(I)-catalyzed Diels-Alder reaction of a boron-functionalized enyne is the key step in a two-step reaction cascade interconnecting four simple starting materials to obtain polycyclic multifunctionalized products in good yields and with a very high degree of diastereoselectivity.     

Oligoarenes as molecular backbones of catalysts: synthesis and applications

This feature article highlights our recent work on oligoarene-type catalysts. We developed a synthetic method for multifunctionalized oligoarenes using a repetitive two-step strategy. The method was then applied to the preparation of oligoarene-type phosphines, which were used for palladium-catalyzed cross-coupling of halobenzenes with Grignard reagents.     

Direct synthesis of pyrroles via a silver-promoted three-component reaction involving unusual imidazole ring opening

A novel silver-promoted three-component reaction toward the synthesis of multifunctionalized pyrroles has been developed. This reaction involves an unusual imidazole ring decomposition, presumably via 1,5-isomerization and subsequent hydrolysis.     

Iodotrimethylsilane induced diastereoselective synthesis of tetrahydropyranones by a tandem Knoevenagel-Michael reaction

The synthesis of multifunctionalized tetrahydropyranones has been achieved at room temperature with iodotrimethylsilane by a tandem Knoevenagel condensation of aldehydes with aldol adducts prepared from β-keto esters and aldehydes, followed by a Michael reaction. The reactions are highly diastereoselective affording a single isomer in high yields.     

A three-component synthesis of pyrido[2,3-d]pyrimidines

A new, high yield multicomponent reaction providing multifunctionalized pyrido[2,3-d]pyrimidines in a microwave-assisted one-pot cyclocondensation of α,β-unsaturated esters, amidine systems and malononitrile (or ethyl cyanoacetate) is described (the ‘Victory’ reaction).     

One-pot synthesis and in vivo biological evaluation of new pyrimidine privileged scaffolds as potent anti-inflammatory agents

Research on Chemical Intermediates - A simple methodology has been developed for the synthesis of diverse members of multifunctionalized 4-hydroxy-2-methyl-6-(phenyl)pyrimidine-5-carbonitrile...     

Homonuclear Diels-Alder dimerization of 5-ethenyl-2-phenylsulfanyl-1H-imidazoles and its application to synthesis of 12,12′-dimethylageliferin

Homonuclear Diels-Alder dimerization of various 5-ethenyl-2-phenylsulfanyl-1H-imidazoles provided a novel highly regio- and stereoselective route to the preparation of multifunctionalized 4,5,6,7-tetrahydrobenzimidazoles, which is the basic skeleton of ageliferin, a biologically active pyrrole-imidazole marine alkaloid. The reaction was applied to the synthesis of 12,12′-dimethylageliferin.     

Heteroatom‐embedded Medium‐Sized Cycloalkynes: Concise Synthesis,Structural Analysis,and Reactions

A variety of medium‐sized cycloalkynes were efficiently synthesized by the double Nicholas reaction of cobalt complex and bis(hetero)substituted acyclic compound. The alkyne moiety within the ring has a unique bent structure and high reactivity toward cycloaddition reactions. Furthermore, preparation of multifunctionalized alkynes was achieved by embedding the cycloalkyne within a peptide chain.     

Efficient domino approaches to multifunctionalized fused pyrroles and dibenzo[b,e][1,4]diazepin-1-ones

Efficient domino approaches for the synthesis of multifunctionalized tricyclic fused pyrroles and dibenzo[b,e][1,4]diazepin-1-ones have been established. The reaction pathways were controlled by varying enaminones with different substituted patterns to give a series of new fused pyrroles and dibenzo[b,e][1,4]diazepin-1-ones selectively. The complete anti diastereoselectivity was achieved for the first reaction.     

Biorenewable and mercaptoacetylating building blocks in the Biginelli reaction: synthesis of thiosugar-annulated dihydropyrimidines

A novel version of the Biginelli reaction using an unprotected aldose as a biorenewable aldehyde component and 2-methyl-2-phenyl-1,3-oxathiolan-5-one as a mercaptoacetylating active methylene building block with urea/thiourea is reported. The reaction is nanoclay-catalysed, expeditious and effected under solvent-free microwave irradiation conditions in a one-pot procedure to yield diastereoselectively, thiosugar-annulated multifunctionalized dihydropyrimidines via intramolecular domino cyclocondensation reactions of an isolable intermediate.     

Asymmetric synthesis of multifunctionalized pyrrolines by a ruthenium porphyrin-catalyzed three-component coupling reaction

[reaction: see text] Chiral multifunctionalized pyrrolines have been synthesized by a ruthenium porphyrin catalyzed three-component coupling reaction. In a one-pot reaction, ruthenium porphyrins catalyzed in situ generation of chiral azomethine ylides from chiral diazo esters and imines. Asymmetric 1,3-dipolar cycloaddition reactions of the chiral azomethine ylides with dipolarophiles afforded the corresponding pyrrolines in good yields and high diastereoselectivity (up to 92% de).     

Heteroatom‐embedded Medium‐Sized Cycloalkynes: Concise Synthesis,Structural Analysis,and Reactions

A variety of medium‐sized cycloalkynes were efficiently synthesized by the double Nicholas reaction of cobalt complex and bis(hetero)substituted acyclic compound. The alkyne moiety within the ring has a unique bent structure and high reactivity toward cycloaddition reactions. Furthermore, preparation of multifunctionalized alkynes was achieved by embedding the cycloalkyne within a peptide chain.     

A highly stereoselective organocatalytic tandem aminoxylation/aza-Michael reaction for the synthesis of tetrahydro-1,2-oxazines

A facile stereoselective synthesis of multifunctionalized tetrahydro-1,2-oxazines (THOs) has been achieved by the organocatalyzed asymmetric tandem alpha-aminoxylation/aza-Michael reaction for the C-O/C-N bond formations in moderate to good yields with excellent diastereo- (>99:1 dr) and enantioselectivities (92% to >99% ee).     

Asymmetric cobalt-catalyzed Diels-Alder reactions of a boron-functionalized 1,3-diene with alkynes and allylboration with aldehydes

[Structure: see text] A cobalt(I)-catalyzed Diels-Alder reaction of a 1-boron-functionalized 1,3-diene is the key step in a one-pot reaction interconnecting three simple starting materials to obtain a multifunctionalized product. This product incorporates a stereogenic quaternary center next to a stereogenic secondary alcohol functionality generated with a very high degree of regio- and diastereoselectivity and good enantioselectivity in the presence of a chiral ligand such as (S,S)-Norphos.     

Ruthenium(II)-catalyzed synthesis of hydroxylated arenes with ester as an effective directing group

An unprecedented Ru(II) catalyzed ortho-hydroxylation has been developed for the facile synthesis of a variety of multifunctionalized arenes from easily accessible ethyl benzoates with ester as an efficient directing group. Both the TFA/TFAA cosolvent system and oxidants serve as the critical success factors in this transformation. The reaction demonstrates excellent reactivity, good functional group tolerance, and high yields.     

Highly Regio‐ and Enantioselective Synthesis of N‐Substituted 2‐Pyridones: Iridium‐Catalyzed Intermolecular Asymmetric Allylic Amination

The first iridium‐catalyzed intermolecular asymmetric allylic amination reaction with 2‐hydroxypyridines has been developed, thus providing a highly efficient synthesis of enantioenriched N‐substituted 2‐pyridone derivatives from readily available starting materials. This protocol features a good tolerance of functional groups in both the allylic carbonates and 2‐hydroxypyridines, thereby delivering multifunctionalized heterocyclic products with up to 98 % yield and 99 % ee.     

RhI‐Catalyzed PIII‐Directed C−H Bond Alkylation: Design of Multifunctional Phosphines for Carboxylation of Aryl Bromides with Carbon Dioxide

We report the C?H alkylation of biarylphosphines at the ortho′ position(s) with alkenes by using rhodium(I) catalysis, which provides straightforward access to a large library of multifunctionalized phosphines. Some of these modified ligands outperformed commercially available phosphines in the Pd‐catalyzed carboxylation of aryl bromides with carbon dioxide in the presence of a photoredox catalyst.