ABSTRACT
A series of phenothiazine based dyes (OMS1-3), comprising different conjugation lengths and numbers of electron deficient (cyanovinyl) moieties with cyanoacrylic acid as an anchor, have been synthesized. The dyes display broad UV-visible absorption, from 389 nm to 484 nm. The higher molar extinction coefficient and longer absorption peak are achieved as the conjugation length and numbers of electron deficient units increase. The cell performance based on these dyes exhibits efficiencies ranging from 0.68-4.00%, compared to a standard N719-based device (PCE = 7.49%) fabricated under similar conditions. Although the OMS3 dye has two electron deficient units between phenothiazine units, an insignificant electron trapping effect is observed. From the results, the OMS3 based cell exhibits the highest short circuit current (J SC) at 8.72 mA cm-2 and the highest open-circuit voltage (V OC) at 0.66 V, together with the best cell performance at 4.00%.
ABSTRACT
An efficient one-pot two-step procedure for asymmetric synthesis of piperidine-fused trans-cycloalkenes is reported. The method comprises the initial enantioselective installation of another cyclopropane ring onto methylenecyclopropanes and the subsequent thermal skeletal rearrangement in which the installed and inherent cyclopropane rings are both opened. A concerted mechanism is proposed for the latter thermal rearrangement reaction together with a closed transition state model.
ABSTRACT
The synthesis of 2,3-disubstituted pyrroles via TMSOTf-assisted cyclization reaction of 3,5,5-trimethyl-2,3-epoxycyclohexan-1-ones incorporating a (3-arylpropargyltosylamino)methyl tether at the C-2 position is described. The reaction starts with an acid-promoted semipinacol rearrangement to give a ring contraction cyclopentanone moiety bearing an arylpropargylaminoacetyl side chain. A subsequent alkyne-ketone metathesis affords the pyrrole derivatives in good yields. The 3,4-disubstituted furan analogues can also be available from 3,5,5-trimethyl-2,3-epoxycyclohexan-1-ones with a tethered arylpropargyl methyl ether at the C-2 position and BF3·OEt2 under an atmosphere of oxygen.
Subject(s)
Alkynes/chemistry , Cyclohexanones/chemistry , Furans/chemical synthesis , Ketones/chemistry , Lewis Acids/chemistry , Pyrroles/chemical synthesis , Furans/chemistry , Molecular Structure , Pyrroles/chemistryABSTRACT
The synthesis of fluorinated azabicycles from tert-butyldimethylsilyl-protected N-containing cyclic enynols using inexpensive BF3·OEt2 is described. In this reaction, BF3 reacts as both the Lewis acid and the fluoride source for cyclization/fluorination of the TBS-protected cyclic N-containing enynols. The method provides an easy access to fluorinated azabicycles where a new C(sp(2))-F bond and a new bicyclic skeleton are generated at ambient temperature within 1-13 min under metal-free reaction conditions.
Subject(s)
Azabicyclo Compounds/chemical synthesis , Cyclohexanols/chemistry , Nitrogen/chemistry , Silanes/chemistry , Azabicyclo Compounds/chemistry , Cyclization , Molecular StructureABSTRACT
Spirolactones, spirotetrahydrofurans, and spiropyrrolidines containing a vicinal cis-diol adjacent to the spiro-carbon center are prepared by one-pot epoxidation/spirocyclization of cyclohex-2-en-1-ols bearing an ester, alcohol, or amide functional side chain at the C(3) position of the ring.
Subject(s)
Cyclohexanols/chemical synthesis , Epoxy Compounds/chemical synthesis , Spiro Compounds/chemical synthesis , Crystallography, X-Ray , Cyclization , Cyclohexanols/chemistry , Epoxy Compounds/chemistry , Models, Molecular , Molecular Structure , Spiro Compounds/chemistry , StereoisomerismABSTRACT
The FeCl(3)-promoted synthesis of 2-azaspiro[4.6]undec-7-ene rings proceeds via ring expansion/cyclization/chlorination of N-tosyl-N-(3-arylpropargyl)-tethered 6-methylbicyclo[4.1.0]heptan-2-ols. This azaspirocyclic ring skeleton can also be obtained in one pot from the tert-butyldimethylsilyl-protected N-tosyl-N-(3-arylpropargyl)-tethered 3-methylcyclohex-2-en-1-ols and diethylzinc/diiodomethane.
