نتایج جستجو برای: spiro heterobicyclic rings

تعداد نتایج: 50633  

Journal: :Organic & biomolecular chemistry 2009
Jun-Ming Mo Yang-Guang Ma Ying Cheng

2-(2-Alkoxycarbonyl-1-arylamino-1-propenyl)benzimidazolium and 5-(2-alkoxycarbonyl-1-arylamino-1-propenyl)triazolium salts were synthesized in good yields from the reaction of benzimidazole and triazole carbenes with ketenimines. Upon treatment with a base, both salts were converted into novel 1,3-dipoles which underwent [3+2] cycloaddition reactions with electron-deficient alkynes and allenes ...

Irradiation of &methyl spiro [2.5] oct-7-en-4-one through its singlet excited state resulted in the formation of 4-methyl spirO [2.5] oct-4-en -6-one. We have used the cyclopropyl moiety in the molecule as a probe to study the operating mechanism in the photochemistry of ?, ?-unsaturated compounds. The results showed that this photoisomerization probably occurs through a concerted process.

Journal: :Nano Energy 2021

Hole transporting materials (HTMs) play essential roles in facilitating hole extraction and suppressing recombination lead halide perovskite solar cells (PSCs). High levels of p-doping HTMs is necessary for achieving high device performance, attributed to an increased electrical conductivity. In this work, we provide evidences that the poor performance PSCs with low doping (i.e., 4 mol% spiro-O...

Journal: :Organic letters 2013
Bandi Ramakrishna Perali Ramu Sridhar

Electrophilic ring opening of spiro-cyclopropanecarboxylated sugars followed by reaction with DBU revealed interesting ring-contraction and ring-expansion reactions depending on the substrate and the kind of hydroxyl protective group present adjacent to the spiro center. A stereoselective method for accessing a new class of carbon chain extended keto-furanoses and C-glycosylated bicyclic compou...

Abdol Hajipour, Amin Zarei, Leila Khazdooz, Nafisehsadat Sheikhan

In the present of methylimidazolium hydrogen sulfate, the synthesis of arylidene heterobicyclic pyrimidinones is studied by condensation of aromatic aldehyde, cyclopentanone, and urea or thiourea. Using solvent-free conditions, non-toxic and inexpensive materials, simple and clean work-up, short reaction times and good yields of the products are the advantages of this method.

Abdol Hajipour, Amin Zarei, Leila Khazdooz, Nafisehsadat Sheikhan

In the present of methylimidazolium hydrogen sulfate, the synthesis of arylidene heterobicyclic pyrimidinones is studied by condensation of aromatic aldehyde, cyclopentanone, and urea or thiourea. Using solvent-free conditions, non-toxic and inexpensive materials, simple and clean work-up, short reaction times and good yields of the products are the advantages of this method.

2013
Seenivasan Karthiga Devi Thothadri Srinivasan Raju Rajesh Raghavachary Raghunathan Devadasan Velmurugan

The mol-ecular conformation of the title compound, C41H29ClN4O3S, is stabilized by intra-molecular C-H⋯O and C-H⋯Cl hydrogen bonds. The thia-zole ring adopts an envelope conformation with the N atom as the flap, while the pyrrolidine ring has a twisted conformation on the N-C bond involving the spiro C atom. The β la-ctam ring makes dihedral angles of 39.74 (15) and 16.21 (16)° with the mean pl...

2005
Jian-Hua Xie Shou-Fei Zhu Yu Fu Ai-Guo Hu Qi-Lin Zhou

Chiral spiro phosphorus ligands including monophosphoramidites and diphosphines, which contained 1,1'-spirobiindane as a backbone, were designed and synthesized. These spiro ligands were proven to be highly efficient for rhodiumand ruthenium-catalyzed asymmetric hydrogenations of prochiral olefins and ketones with excellent enantioselectivities.

Journal: :Organic & biomolecular chemistry 2014
Takao Saito Yoshihiko Sonoki Takashi Otani Noriki Kutsumura

A new approach towards the synthesis of indole derivatives via triflic acid-promoted cycloisomerization with rearrangement of 2-(alkyn-1-yl)phenyl isothiocyanates and 2-(alkyn-1-yl)phenyl isocyanates has been achieved. By this methodology, structurally diverse types of indole derivatives such as thieno- and furo-indoles, spiro-indolethiones, spiro-oxindoles, and 3-alkylidene-oxindoles were synt...

Journal: :Japanese journal of pharmacology 1953
W C LEE

In an effort to develop new and possibly better types of barbiturates, suitable for intravenous use, a large number of spiro-barbiturates have been prepared by a ring closure on the 5-carbon atom of the barbituric acid and afforded for pharmacologic study. Spiro(2'-ethyl-3',5'-dimethyl cyclopentane) thio-barbituric acid appears to be the most promising product of a series of 50 analogues. Stoel...

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