3014-80-0Relevant articles and documents
Development of new catalytic enantioselective formation of methylenelactam-based N,O-spirocyclic compounds via ring opening-asymmetric reclosure of hydroxylactams
Sengoku, Tetsuya,Miyoshi, Ayako,Tsuda, Tamaki,Inuzuka, Toshiyasu,Sakamoto, Masami,Takahashi, Masaki,Yoda, Hidemi
, (2020/05/18)
Catalytic enantioselective formation of methylenelactam-based N,O-spirocyclic compounds is developed. Hydroxylactams prepared from N-carbonyl phthalimides and β-amido functionalized allylboronates underwent ring opening-asymmetric reclosure in the presence of catalytic amounts of MgBr2 and a chiral aminophenol to afford the corresponding N,O-spirocyclic compounds in excellent yields and high enantioselectivities.
Regioselective hydration and deprotection of chiral, dissymmetric iminodinitriles in the scope of an asymmetric strecker strategy
Rossi, Jean-Christophe,Marull, Marc,Boiteau, Laurent,Taillades, Jacques
, p. 662 - 668 (2007/10/03)
The controlled, selective decomposition of dissymmetric iminodinitriles (DIDN) of formula RCH(CN)-NH-C(CN)R′R″ (considered as N-protected alpha-aminonitriles), is a critical issue for an original asymmetric Strecker strategy previously outlined by us for the enantioselective synthesis of amino acids. This strategy, derived from Harada's work, involves a double sequence of (i) stereoselective Strecker condensation of a chiral ketone R′R″CO with NH3 and HCN, followed by (ii) stereoselective Strecker condensation with an aldehyde RCHO and HCN, then (iii) regioselective retro-Strecker decomposition of the DIDN intermediate to release the target alpha-aminonitrile. In addition to the use of quite simple, cheap cyclic ketones (e.g. carvone derivatives) as chiral auxiliaries, another great advantage of this strategy is that step (iii) enables the recovery of the chiral ketone and hence its reuse. While our previous investigations on step (iii) under various conditions, either preceded or followed by the hydration of the secondary nitrile group RH(CN)- into an amide, had shown insufficient selectivity, we succeeded in the regioselective hydration of the secondary nitrile of DIDN without significant racemisation, by using a large excess of hydrogen peroxide in methanolic/aqueous ammonia (pH 12.5) at low temperature. The resulting imino nitrile/amide compound was then classically decomposed in acidic medium through a retro-Strecker reaction, affording the chiral alpha-amino amide. Alternately, the regioselective retro-Strecker decomposition of the tertiary moiety of the DIDN was achieved by reaction with silver cation in aqueous nitric acid, also without significant racemisation, thus establishing an original, enantioselective synthesis of alpha-aminonitriles. In both reactions, the chiral ketonic auxiliary resulting from DIDN decomposition was recovered in good yields. Wiley-VCH Verlag GmbH & Co. KGaA, 2007.
Herbicidal imidazolones
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, (2008/06/13)
Compounds such as Formula I having herbicidal utility are disclosed: STR1 wherein Q is STR2 R1 is H; alkyl, haloalkyl or halogen R2 is C1 -C2 alkyl optionally substituted with one or more halogens, OR8, CN, COR9, CO2 R31 or CONR32 R33 ; CN; CO2 R34 ; CONR35 R36 ; S(O)n R8 ; S(O)n NR19 R8 or COR37 ; or R1 and R2 can be taken together along with the carbon to which they are attached to form C=CHCO2 R31 ; C=(CH3)CO2 R31 ; C=(C2 H5)CO2 R31 ; C=CHCONR32 R33 ; C=C(CH3)CONR32 R33 or C=C(C2 H5)CONR32 R33.
