A One-Step Synthesis of Alkyl 2-Oxo-3-alkenoates from Alkenyl Grignard Reagents and Dialkyl Oxalates
作者:M. Rambaud、M. Bakasse、G. Duguay、J. Villieras
DOI:10.1055/s-1988-27642
日期:——
The reaction of alkenyl Grignard reagents with dialkyl oxalates at 80°C in an ether/tetrahydrofuran mixture (1:1) leads to the formation of the corresponding alkyl 2-oxo-3-alkenoates in high yields. Thus a mild and convenient one-step synthesis of 3-isopropenyl-substituted 2-oxoesters is described.
REAGENT FOR ORGANIC SYNTHESIS REACTION CONTAINING ORGANIC TRIOL BORATE SALT
申请人:Miyaura Norio
公开号:US20100087646A1
公开(公告)日:2010-04-08
[Problem] To provide an organoboron compound-containing reagent for organic synthesis reactions which undergoes no trimerization with dehydration, does not necessitate activation with a base, and is stable and highly active.
[Means for Solving Problems] The reagent for organic synthesis reactions contains an organic triol borate salt represented by any of the general formulae (I) to (III) and general formula (XVI): (wherein R
1
represents alkyl, alkenyl, etc.; R
2
represents optionally substituted alkyl, alkenyl, alkynyl, etc. or represents hydrogen; m
+
represents an alkaline metal ion, phosphonium ion, or given ammonium ion; M
2+
represents an alkaline earth metal; X represents halogen or alkoxide; Y represents an alkali metal ion, etc.; A represents optionally substituted methylene; and n represents an integer).
We report the first desymmetrization of bisallylic amides by enantioselective bromocyclization with BINAP monoxide as a catalyst. Depending upon the substitution pattern of the alkene moieties, densely functionalized, opticallyactiveoxazoline or dihydrooxazine compounds were obtained in a highly stereoselective manner. The remaining alkene moiety was subjected to various functional group manipulations
Size-Exclusion Borane-Catalyzed Domino 1,3-Allylic/Reductive Ireland-Claisen Rearrangements: Impact of the Electronic and Structural Parameters on the 1,3-Allylic Shift Aptitude
reductive Ireland–Claisenrearrangement through borane‐mediated hydrosilylation is reported. The method employs a borane catalyst with a special structural design and affords access to synthetically relevant products with high diastereoselectivity. Depending on electronic and structural parameters, the reaction can be coupled with a 1,3‐allylic shift, thus the valence isomer of the Ireland–Claisen product
Reinvestigation of the grignard reactions with formic acid. A convenient method for preparation of aldehydes
作者:Fumie Sato、Kaoru Oguro、Hiroshi Watanabe、Masao Sato
DOI:10.1016/s0040-4039(00)78630-8
日期:1980.1
Grignard reagents react with formic acid in tetrahydrofuran to produce aldehydes in relatively good yields Various aldehydes such as alkyl, aryl, allyl, benzyl and vinyl aldehydes were prepared from the corresponding Grignard reagents. The reaction with vinyl Grignard reagents proceeded with retention of configuration.