Rapid Access to Polyfunctionalized 3,4-Dihydroquinazolinones through a Sequential<i>N</i>-Acyliminium Ion Mannich Reaction Cascade
作者:Rajiv T. Sawant、Marc Y. Stevens、Luke R. Odell
DOI:10.1002/ejoc.201501178
日期:2015.12
sequential cyclization-Mannich reaction of unactivated ketones, o-formyl carbamates and primary amines has been developed. Cyclic N-acyliminium ions are generated in situ from the carbamate and amine starting materials. This metal-free cascade protocol provides rapid access to structurallydiverse 3,4-dihydroquinazolinones in good to excellent yields with high regioselectivity for the terminal methyl group
Hydrophobically directed, catalyst-free, multi-component synthesis of functionalized 3,4-dihydroquinazolin-2(1H)-ones
作者:Daggupati V. Ramana、B. Vinayak、V. Dileepkumar、U. S. N. Murty、L. Raju Chowhan、M. Chandrasekharam
DOI:10.1039/c6ra00381h
日期:——
A one-potthree-componentreaction of o-formyl carbamate, a primary amine, a nucleophile (1H-indole or 2-napthol) in water generated a variety of functionalised 3,4-dihydroquinazolin-2(1H)-one derivatives. The reaction operated under catalyst-free conditions involves a Mannich type reaction followed by intramolecular cyclization and produced good to excellent yields of the products with a wide range
N-phenylcarbamates having a microbicide insecticide and acaricide effect
申请人:——
公开号:US20040023806A1
公开(公告)日:2004-02-05
The invention relates to novel compounds of the formula I
1
in which
A is —CH
2
O— or —CH═N—;
R
1
is C
1
-C
4
-alkyl or cyclopropyl;
R
2
is C
1
-C
6
-alkyl, C
2
-C
6
-alkenyl or C
2
-C
6
-alkynyl or is C
1
-C
6
-alkyl substituted by from 1 to 5 fluorine atoms;
R
3
denotes the radicals defined in the description;
R
5
is hydrogen, C
1
-C
4
-alkyl, C
1
-C
2
-alkoxymethyl, C
1
-C
2
-alkylthiomethyl, C
1
-C
3
-haloalkylmethyl, C
2
-C
4
-alkenyl, C
2
-C
4
-alkynyl, C
1
-C
3
-alkylcarbonyl or C
1
-C
2
-alkoxycarbonyl, and
R
6
is C
1
-C
4
-alkyl, which are suitable in agriculture for controlling acarids and insects and for preventing the infestation of crop plants by phytopathogenic fungi.
A novel AcOH-promoted metal-free cascade N-acyliminium ion/aza-Prins cyclization of o-formyl carbamates and homoallylamines is reported. This one-pot protocol provides efficient and rapid access to masked cis-hydroxyhexahydropyrido[1,2-c]quinazolin-6-ones with concomitant generation of...
Microwave-Assisted Branching Cascades: A Route to Diverse 3,4-Dihydroquinazolinone-Embedded Polyheterocyclic Scaffolds
作者:Rajiv T. Sawant、Marc Y. Stevens、Christian Sköld、Luke R. Odell
DOI:10.1021/acs.orglett.6b02774
日期:2016.10.21
A novel metal-free microwave-assisted branchingcascades strategy for the efficient synthesis of 3,4-dihydroquinazolinone-embedded polyheterocyclic scaffolds is reported. Starting from in situ generated key N-acyliminium ion precursors, 12 distinct and skeletally diverse polycyclic frameworks were accessed in a single step/pot via adjustment of the nucleophile(s) and reaction conditions. Postcascade