[신간의 별자리x] 우리/미술, 그리고 ‘슬픔의 박물관’

Sterically encumbered Lewis acid and Lewis base combinations do not undergo the ubiquitous neutralization reaction to form "classical" Lewis acid/Lewis base adducts. Rather, both the unquenched Lewis acidity and basicity of such sterically "frustrated Lewis pairs (FLPs)" is available to carry out unusual reactions. Typical examples of frustrated Lewis pairs are inter- or intramolecular combinations of bulky phosphines or amines with strongly electrophilic RB(C(6)F(5))(2) components. Many examples of such frustrated Lewis pairs are able to cleave dihydrogen heterolytically. The resulting H(+)/H(-) pairs (stabilized for example, in the form of the respective phosphonium cation/hydridoborate anion salts) serve as active metal-free catalysts for the hydrogenation of, for example, bulky imines, enamines, or enol ethers. Frustrated Lewis pairs also react with alkenes, aldehydes, and a variety of other small molecules, including carbon dioxide, in cooperative three-component reactions, offering new strategies for synthetic chemistry.

Frustrated Lewis pairs: metal-free hydrogen activation and more.

Isatins As Privileged Molecules in Design and Synthesis of Spiro-Fused Cyclic Frameworks

Frustrierte Lewis‐Paare: metallfreie Wasserstoffaktivierung und mehr

Driven by the potential advantages and promising applications of organic solar cells, donor-acceptor (D-A) polymers have been intensively investigated in the past years. One of the strong electron-withdrawing groups that were widely used as acceptors for the construction of D-A polymers for applications in polymer solar cells and FETs is isoindigo. The isoindigo-based polymer solar cells have reached efficiencies up to approximate to 7% and hole mobilities as high as 3.62 cm(2) V-1 s(-1) have been realized by FETs based on isoindigo polymers. Over one hundred isoindigo-based small molecules and polymers have been developed in only three years. This review is an attempt to summarize the structures and properties of the isoindigo-based polymers and small molecules that have been reported in the literature since their inception in 2010. Focus has been given only to the syntheses and device performances of those polymers and small molecules that were designed for use in solar cells and FETs. Attempt has been made to deduce structure-property relationships that would guide the design of isoindigo-based materials. It is expected that this review will present useful guidelines for the design of efficient isoindigo-based materials for applications in solar cells and FETs.

25th Anniversary Article: Isoindigo-Based Polymers and Small Molecules for Bulk Heterojunction Solar Cells and Field Effect Transistors

The reaction of the di-O-trimethylsilyl derivative of 2-hydroxynicotinic acid with methyl phosphodichloridite afforded 2-methoxy-1,3,2-dioxaphosphorino[4,5-b]pyridin-4(4H )-one. The NMR spectrkscopic data suggest that the reaction of the latter with hexafluoroacetone produces unstable 2-methoxy-2,5-dioxo-4,4-bis(trifluoromethyl)-4,5-dihydro-1,3,2-dioxaphosphepino[4,5-b]pyridine, which is readily transformed into 9-methyl-2,5-dioxo-4,4- bis(trifluoromethyl)-4,5-dihydro-1,3,2-dioxaphosphepino[4,5-b]pyrid-9-inium-2-oate. The structure of the hydrolysis product of the latter, viz., 1-methyl-3-(2-hydroxy-3,3,3-trifluoro-2- trifluoromethylpropanoyl)pyridin-2-one, was established by X-ray diffraction analysis.

Reaction of 2-methoxy-1,3,2-dioxaphosphorino[4,5-b]pyridin-4(4H)-one with hexafluoroacetone

Steviol reacted with benzyl bromide and 1,9-dibromononane in the system KOH-DMSO to give the corresponding O-alkylation products at the carboxy group. The reaction of steviol with methyl iodide was accompanied by alkylation of the hydroxy group and rearrangement of the carbon skeleton.

O-Alkylation of diterpenoid steviol in the system KOH-DMSO

The transformation of the carboxy and keto groups of the isosteviol (ent-16-ketobeyeran-19-oic acid) diterpenoid was used to synthesize its new nitrogen-containing derivatives, including Schiff bases by the C4 and C16 atoms of the isosteviol frame The structure of the resulting compounds was established by X-ray diffraction

Synthesis of Schiff bases on the basis of the isosteviol terpenoid

The reaction of 16-hydroximinoisosteviol with dihaloalkanes in the KOH-DMSO results in coupling of two isosteviol carcasses by the carboxy groups. The same products were previously synthesized by hydroximination of isosteviol diesters.

Alkylation of the isosteviol terpenoid and its oxime with dibromoalkanes in the KOH-DMSO system

Acylation of amino alcohols with isosteviol chloride, depending on the reactant ratio, leads to formation of either bis-isosteviol derivatives or N-acylation products. Reactions of aromatic diamines with 2 equiv of isosteviol chloride give the corresponding N,N′-bis(isostevioyl) derivatives.

Rashid Z. Musin

Papers

Reaction of 2-methoxy-1,3,2-dioxaphosphorino[4,5-b]pyridin-4(4H)-one with hexafluoroacetone

O-Alkylation of diterpenoid steviol in the system KOH-DMSO

Synthesis of Schiff bases on the basis of the isosteviol terpenoid

Alkylation of the isosteviol terpenoid and its oxime with dibromoalkanes in the KOH-DMSO system

Chemistry and structure of diterpenoids: X. Isosteviol amides