PMID- 35496344
OWN - NLM
STAT- PubMed-not-MEDLINE
LR  - 20220716
IS  - 2046-2069 (Electronic)
IS  - 2046-2069 (Linking)
VI  - 12
IP  - 20
DP  - 2022 Apr 22
TI  - Sonochemistry in an organocatalytic domino reaction: an expedient multicomponent 
      access to structurally functionalized dihydropyrano[3,2-b]pyrans, 
      spiro-pyrano[3,2-b]pyrans, and spiro-indenoquinoxaline-pyranopyrans under ambient 
      conditions.
PG  - 12843-12857
LID - 10.1039/d2ra01917e [doi]
AB  - A highly convenient and sustainable one-pot approach for the diversely-oriented 
      synthesis of a variety of medicinally privileged amino-substituted 
      4,8-dihydropyrano[3,2-b]pyran-3-carbonitriles, and 
      spiro[indoline-3,4'-pyrano[3,2-b]pyran]-3-carbonitrile/carboxylate derivatives on 
      the basis of a domino three-component reaction of readily available carbonyl 
      compounds including aryl aldehydes or isatins, active methylene compounds, and 
      kojic acid as a Michael donor using secondary amine catalyst l-proline under 
      ultrasound irradiation in aqueous ethanolic solution at ambient temperature has 
      been developed. This methodology can involve the assembly of C-C, C[double bond, 
      length as m-dash]C, C-O, C-N bonds via a one-pot operation, and following this 
      protocol, a series of novel amino-substituted 
      spiro[indeno[1,2-b]quinoxaline-11,4-pyrano[3,2-b]pyran]-3-carbonitrile/carboxylates 
      have been synthesized. The practical utility of this method was found to be very 
      efficient for scale-up reaction and other useful transformations. The methodology 
      provides significant advantages including mild reaction conditions, 
      energy-efficiency, short reaction time, fast reaction, simple work-up procedure, 
      broad functional group tolerances, utilization of reusable catalyst, green 
      solvent system, being metal-free, ligand-free, waste-free, inexpensive, etc. 
      Excellent chemical yields have been achieved without using column chromatography. 
      To address the issues of green and more sustainable chemistry, several metrics 
      including Atom Economy (AE), Reaction Mass Efficiency (RME), Atom efficiency, 
      E-factor, Process Mass Intensity (PMI), and Carbon Efficiency (CE) have been 
      quantified for the present methodology that indicates the greenness of the 
      present protocol.
CI  - This journal is (c) The Royal Society of Chemistry.
FAU - Borah, Biplob
AU  - Borah B
AUID- ORCID: 0000-0002-1164-750X
AD  - School of Applied Material Sciences, Centre for Applied Chemistry, Central 
      University of Gujarat Sector-30 Gandhinagar-382030 Gujarat India 
      rchowhan@cug.ac.in.
FAU - Bora, Jahnu
AU  - Bora J
AD  - School of Applied Material Sciences, Centre for Applied Chemistry, Central 
      University of Gujarat Sector-30 Gandhinagar-382030 Gujarat India 
      rchowhan@cug.ac.in.
FAU - Ramesh, Pambala
AU  - Ramesh P
AD  - CSIR-Indian Institute of Chemical Technology Hyderabad-50007 India.
FAU - Chowhan, L Raju
AU  - Chowhan LR
AUID- ORCID: 0000-0002-5434-4488
AD  - School of Applied Material Sciences, Centre for Applied Chemistry, Central 
      University of Gujarat Sector-30 Gandhinagar-382030 Gujarat India 
      rchowhan@cug.ac.in.
LA  - eng
PT  - Journal Article
DEP - 20220428
PL  - England
TA  - RSC Adv
JT  - RSC advances
JID - 101581657
PMC - PMC9048984
COIS- There are no conflicts to declare.
EDAT- 2022/05/03 06:00
MHDA- 2022/05/03 06:01
PMCR- 2022/04/28
CRDT- 2022/05/02 06:49
PHST- 2022/03/24 00:00 [received]
PHST- 2022/04/19 00:00 [accepted]
PHST- 2022/05/02 06:49 [entrez]
PHST- 2022/05/03 06:00 [pubmed]
PHST- 2022/05/03 06:01 [medline]
PHST- 2022/04/28 00:00 [pmc-release]
AID - d2ra01917e [pii]
AID - 10.1039/d2ra01917e [doi]
PST - epublish
SO  - RSC Adv. 2022 Apr 28;12(20):12843-12857. doi: 10.1039/d2ra01917e. eCollection 
      2022 Apr 22.