Boron Trifluoride Mediated Ring-Opening Reactions of trans-2-Aryl-3-nitro-cyclopropane-1,1-dicarboxylates. Synthesis of Aroylmethylidene Malonates as Potential Building Blocks for Heterocycles
摘要:
trans-2-Aryl-3-nitro-cyclopropane-1,1-dicarboxylates, upon treatment with BF3 center dot OEt2, undergo ring-opening rearrangement and the Nef reaction to give aroylmethylidene malonates. The products are found to be potential precursors for heterocycles, such as imidazoles, quinoxalines, and benzo[1,4]thiazines.
Efficient Stereoselective Synthesis of Nitrocyclopropanes by the Oxidative Cyclization of Michael Adducts of Nitroolefins with Activated Methylene Compounds
作者:Renhua Fan、Yang Ye、Weixun Li、Lingfei Wang
DOI:10.1002/adsc.200800452
日期:2008.11.3
An efficientoxidative cyclopropanation of the Michaeladducts of nitroolefins with activatedmethylenecompounds by the combination of iodobenzene diacetate and tetrabutylammonium iodide is reported. Highly functionalized nitrocyclopropanes are synthesized in moderate to good yields via the Michael addition and cyclopropanation with high diastereoselectivity and enantioselectivity under mild conditions
Asymmetric urea compound and process for producing asymmetric compound by asymmetric conjugate addition reaction with the same as catalyst
申请人:Takemoto Yoshiji
公开号:US20060161006A1
公开(公告)日:2006-07-20
The present invention relates to a production method of asymmetric compound (IV) which includes conjugately adding nucleophilic reagent (III) to compound (II) in the presence of asymmetric urea compound (I). The present invention provides a non-metallic asymmetric catalyst capable of realizing a highly stereoselective asymmetric conjugate addition reaction in a high yield, and an advantageous production method of an asymmetric compound by an asymmetric conjugate addition reaction using the asymmetric catalyst.
wherein X is an oxygen atom or a sulfur atom; C*, C** and C*** are asymmetric carbons; R
1
, R
2
, R
4
, R
5
, R
8
, R
9
and R
10
are each a lower alkyl group optionally having substituent(s) and the like, or R
4
and R
5
and the like in combination optionally form a homocyclic ring optionally having substituent(s) and the like; R
3
is an aryl group optionally having substituent(s) and the like; R
6
and R
7
are each a hydrogen atom and the like; Nu is —CR
16
(COR
17
)(COR
18
) wherein R
16
, R
17
and R
18
are each a lower alkyl group optionally having substituent(s) and the like, and the like; and EWG is an electron withdrawing group.
ASYMMETRIC UREA COMPOUND AND PROCESS FOR PRODUCING ASYMMETRIC COMPOUND BY ASYMMETRIC CONJUGATE ADDITION REACTION WITH THE SAME AS CATALYST
申请人:Sumitomo Chemical Company, Limited
公开号:EP1640361A2
公开(公告)日:2006-03-29
The present invention relates to a production method of asymmetric compound (IV) which includes conjugately adding nucleophilic reagent (III) to compound (II) in the presence of asymmetric urea compound (I). The present invention provides a non-metallic asymmetric catalyst capable of realizing a highly stereoselective asymmetric conjugate addition reaction in a high yield, and an advantageous production method of an asymmetric compound by an asymmetric conjugate addition reaction using the asymmetric catalyst.
wherein X is an oxygen atom or a sulfur atom; C*, C** and C*** are asymmetric carbons; R1, R2, R4, R5, R8, R9 and R10 are each a lower alkyl group optionally having substituent(s) and the like, or R4 and R5 and the like in combination optionally form a homocyclic ring optionally having substituent(s) and the like; R3 is an aryl group optionally having substituent(s) and the like; R6 and R7 are each a hydrogen atom and the like; Nu is -CR16(COR17) (COR18) wherein R16, R17 and R18 are each a lower alkyl group optionally having substituent(s) and the like, and the like; and EWG is an electron withdrawing group.