4-(Succinimido)-1-butane sulfonic acid as a Brönsted acid catalyst for the synthesis of pyrano[4,3-b]pyran derivatives using thermal and ultrasonic irradiation
作者:Nader Ghaffari Khaligh、Sharifah Bee Abd Hamid
DOI:10.1016/s1872-2067(14)60307-7
日期:2015.5
Abstract 4-(Succinimido)-1-butane sulfonic acid was shown to be an efficient and reusable Bronsted acid catalyst for the synthesis of pyrano[4,3- b ]pyran derivatives using thermal and ultrasonic conditions. The catalyst was prepared by mixing succinimide and 1,4-butanesultone, which is simpler and safer than the preparation of succinimide sulfonic acid. This method has the advantages of high yield
A mild, simple and convenient procedure for the synthesis of spiro-oxindole heterocycles containing fused 4H-pyran ring and also bis-2-amino-4H-pyrans derivatives was described using C4(DABCO-SO3H)2·4Cl as a nano, efficient, cheap, and reusable catalyst under mild and homogeneous conditions.
Perchloric acid modified-cellulose: a versatile, novel and biodegradable heterogeneous solid acid catalyst for single-pot synthesis of novel bis-pyran annulated heterocyclic scaffolds under solvent-free conditions
作者:Tabassum Khan、Zeba N. Siddiqui
DOI:10.1039/c4nj00529e
日期:——
the synthesis of novel bis-pyran annulated heterocyclic scaffolds (4a–r) using cellulose–perchloric acid (CPA) as an eco-friendly, biodegradable and recyclable catalyst in excellent yields undersolvent-freeconditions. Other remarkable features of this environmentally benign protocol are short reaction time, a wide range of functional group tolerance, use of inexpensive heterogeneouscatalyst, and
1H-imidazol-3-ium tricyanomethanide {[HIM]C(CN)3} as a nanostructured molten salt catalyst: application to the synthesis of pyrano[4,3‐b]pyrans
作者:Mohammad Ali Zolfigol、Meysam Yarie、Saeed Baghery、Abbas Khoshnood、Diego A. Alonso
DOI:10.1007/s11164-016-2826-y
日期:2017.5
Additionally, the catalytic activity of [HIMI]C(CN)3} (1, 2 mol%) has been tested in a three-component domino Knoevenagel condensation reaction. A range of structurally diverse aromatic aldehydes (2a–p), malononitrile (3), and 4‐hydroxy‐6‐methyl‐2 H ‐pyran‐2‐one (4) are tolerated for the synthesis of 2-amino-7-methyl-5-oxo-4-aryl-4,5-dihydropyrano[4,3-b]pyran-3-carbonitrile derivatives (5a–p) under neat conditions
One-pot synthesis of chromenes in the presence of nano-cellulose/Ti<sup>(IV)</sup>/Fe<sub>3</sub>O<sub>4</sub> as natural-based magnetic nano-catalysts under solvent free conditions
作者:Raziyeh Gholami、Abdolhamid Bamoniri、Bi Bi Fatemeh Mirjalili
DOI:10.1039/d2ra05057a
日期:——
such as XRD, SEM, FT-IR, BET, EDX, TEM, TGA and VSM were used to characterize the catalysts. Then, the identified catalysts were used for the synthesis of various chromene skeletons via reaction of malononitrile, aldehyde and dimedone, 4-hydroxycoumarine or 2-naphthole at 70 °C under solvent free conditions. The spectroscopic methods used to determine the structure of the products include 13C NMR, 1H NMR