- Synthesis of trans-2-Substituted Cyclopropylamines from α-Chloroaldehydes
-
Cyclopropylamines are prevalent in pharmaceuticals and agrochemicals. Herein, we report the synthesis of trans-2-substituted cyclopropylamines in high diastereoselectivity from readily available α-chloroaldehydes. The reaction proceeds via trapping of an electrophilic zinc homoenolate with an amine followed by ring closure to generate the cyclopropylamine. We have also observed that cyclopropylamine cis/trans-isomerization occurs in the presence of zinc halide salts and that this process can be turned off by the addition of a polar aprotic cosolvent.
- West, Michael S.,Mills, L. Reginald,McDonald, Tyler R.,Lee, Jessica B.,Ensan, Deeba,Rousseaux, Sophie A. L.
-
supporting information
p. 8409 - 8413
(2019/10/14)
-
- Carbene-Catalyzed α-Carbon Amination of Chloroaldehydes for Enantioselective Access to Dihydroquinoxaline Derivatives
-
An NHC-catalyzed α-carbon amination of chloroaldehydes was developed. Cyclohexadiene-1,2-diimines are used as amination reagents and four-atom synthons. Our reaction affords optically enriched dihydroquinoxalines that are core structures in natural products and synthetic bioactive molecules.
- Huang, Ruoyan,Chen, Xingkuan,Mou, Chengli,Luo, Guoyong,Li, Yongjia,Li, Xiangyang,Xue, Wei,Jin, Zhichao,Chi, Yonggui Robin
-
supporting information
p. 4340 - 4344
(2019/06/14)
-
- Cascade Trisulfur Radical Anion (S3?-) Addition/Electron Detosylation Process for the Synthesis of 1,2,3-Thiadiazoles and Isothiazoles
-
Trisulfur radical anion (S3?-) mediated reactions with in situ formed azoalkenes and α,β-usaturated N-sulfonylimines for the construction of 1,2,3-thiadiazoles and isothiazoles has been developed. S3?- is in situ generated from potassium sulfide in DMF. These two approaches provide a new, safe, and simple way to construct 4-subsituted 1,2,3-thiadiazoles, 5-subsituted 1,2,3-thiadiazoles, and isothiazole in good yields. The reactions include the formation of the new C-S and N-S bonds via S3?- addition and electron detosylation under mild conditions.
- Liu, Bei-Bei,Bai, Hui-Wen,Liu, Huan,Wang, Shun-Yi,Ji, Shun-Jun
-
p. 10281 - 10288
(2018/07/25)
-
- Carbene and Acid Cooperative Catalytic Reactions of Aldehydes and o-Hydroxybenzhydryl Amines for Highly Enantioselective Access to Dihydrocoumarins
-
A highly enantioselective method for quick access to dihydrocoumarins is reported. The reaction involves a cooperative catalytic process with carbene and in situ generated Br?nsted acid as the catalysts. α-Chloro aldehyde and readily available and stable
- Chen, Xingkuan,Song, Runjiang,Liu, Yingguo,Ooi, Chong Yih,Jin, Zhichao,Zhu, Tingshun,Wang, Hongling,Hao, Lin,Chi, Yonggui Robin
-
supporting information
p. 5892 - 5895
(2017/11/10)
-
- Trichloromethanesulfonyl chloride: A chlorinating reagent for aldehydes
-
Trichloromethanesulfonyl chloride (CCl3SO2Cl), a commercially available reagent, has been found to perform efficiently in the α-chlorination of aldehydes, including its catalytic asymmetric version, under very mild reaction conditions. Under our reaction conditions, this compound outperforms typical chlorinating reagents for organic synthesis, facilitates workup and purification of the product, and minimizes the formation of toxic, chlorinated organic waste.
- Jimeno, Ciril,Cao, Lidong,Renaud, Philippe
-
p. 1251 - 1255
(2016/02/19)
-
- An organocascade approach to α,α-chlorofluoroalcohols
-
Abstract Fluorinated, tetrasubstituted, carbon stereocenters are challenging to install enantioselectively. gem-Chlorofluoro compounds contain a fluorinated, tetrasubstituted stereocenter, and are an entrée into other such compounds. We report herein the first catalytic, enantioselective method to prepare gem-chlorofluoro compounds from unfunctionalized aldehydes. This one-pot method precludes the isolation of volatile and/or reactive α-haloaldehyde intermediates.
- Hayes, Montgomery D.,Rodríguez-Alvarado, Melanie,Brenner-Moyer, Stacey E.
-
supporting information
p. 4718 - 4720
(2015/08/06)
-
- Synthesis of 3-arylcoumarins through N-heterocyclic carbene catalyzed condensation and annulation of 2-chloro-2-arylacetaldehydes with salicylaldehydes
-
The condensation reaction of 2-chloro-2-arylacetaldehyde with salicylaldehyde catalyzed by N-heterocyclic carbene (NHC) leading to 3-arylcoumarin was studied. A number of 3-arylcoumarin derivatives were obtained in good to excellent yields via this umpolung reaction. This reaction is facile and experimentally simple and mild.
- Jiang, Yuansong,Chen, Wanzhi,Lu, Weimin
-
p. 3669 - 3676
(2013/05/08)
-
- Synthesis of 1,1-bisphosphono-2-aza-1,3-dienes, a new class of electron-deficient azadienes
-
1,1-Bisphosphono-2-aza-1,3-dienes are formed by 1,4-dehydrohalogenation of the corresponding N-(bisphosphonomethyl)-α-haloimines in moderate to good yields. The precursors could be formed by condensation of bisphosphono-amines and the corresponding α-haloaldehydes.
- Masschelein, Kurt G.R.,Stevens, Christian V.
-
p. 4336 - 4338
(2008/09/21)
-
- Use of phenylselenium trichloride for simple and rapid preparation of α-phenylselanyl aldehydes and ketones
-
α-Phenylselanyl aldehydes are prepared on a large scale by reaction of PhSeCl3 with the corresponding aldehydes in acetonitrile without isolation of the intermediate dichloro adducts. This method has been applied to α-phenylselanyl ketones deri
- Houllemare, Didier,Ponthieux, Sylvain,Outurquin, Francis,Paulmier, Claude
-
p. 101 - 106
(2007/10/03)
-
- Reaction of epoxides with activated DMSO reagent. General method for synthesis of α-chlorocarbonyl compounds: Application in asymmetric synthesis of (3S)-2,3-oxidosqualene
-
Reaction of a variety of epoxides with DMSO-Oxalyl chloride in the presence of a catalytic amount of methanol and a base was studied. Disubstituted epoxides gave α-chloroketones in high yields. Aliphatic terminal epoxide underwent opening reaction to provide α-chloroketone as a major product. Trisubstituted epoxides provided α-chloroketones as major products through the formation of more stable carbocation. In case of a homoallylic alcohol, enedione was obtained. The efficiency of the method was shown by applying it to the enantioselective synthesis of (3S)-2,3-oxidosqualene.
- Raina, Sushil,Singh, Vinod K.
-
p. 2467 - 2476
(2007/10/02)
-
- Kinetic Resolution of Racemic Aldehydes by Enantioselective Alkylation
-
Various types of racemic aldehydes were kinetically resolved with diethylzinc in the presence of a catalytic amount of a chiral β-amino alcohol.Kinetic resolution of racemic chloro(phenyl)acetaldehyde gave an optically active form as an unchanged substrate, which could be converted into styrene oxide in high optical purity (97.5percent ee).
- Hayashi, Masahiko,Miwata, Hiroshi,Oguni, Nobuki
-
p. 1167 - 1171
(2007/10/02)
-
- REACTIVITY OF α-ARYLSELENO-ALDEHYDES TOWARDS HALOGENS AND BENZENESELENENYL CHLORIDE
-
Chlorination of α-seleno-aldehydes bearing an α-hydrogen gives selenium dichlorides which decompose into α-chloro α-seleno-aldehydes and α-chloroenal.Bromination, in all cases, and chlorination for the other α-seleno-aldehydes lead to the α-halogenoaldehydes.
- Paulmier, Claude,Outurquin, Francis,Plaquevent, Jean-Christophe
-
p. 5893 - 5896
(2007/10/02)
-
- Facile Conversion of Epoxides to Chlorohydrins with Titanium(IV) Chloride/1,8-Diazabicycloundec-7-ene
-
A series of epoxides has been converted to the analogous chlorohydrins by treatment with titanium(IV) chloride and 1,8-diazabicycloundec-7-ene.This procedure tolerates acetal protecting groups normally labile to aqueous acids, and when used in conjunction with the Sharpless epoxidation protocols, it allows the preparation of chiral chlorodiols selectively protected at one hydroxy group.
- Spawn, Carol-Lynn,Drtina, Gary J.,Wiemer, David F.
-
p. 315 - 317
(2007/10/02)
-
- Molecular Rearrangements. 13. Kinetics and Mechanism of Rearrangements of Some Ring-Substituted α-Chlorostyrene Oxides and trans-β-Chlorostyrene Oxides.
-
The synthesis of certain phenyl-substituted derivatives of the isomeric trans-β-chlorostyrene oxides (6) and α-chlorostyrene oxides (7) are reported.The kinetics of rearrangement of 6 (X = p-CH3, H, p-Br, m-Cl, p-NO2) to phenylchloroacetaldehydes (12) in CCl4 buffered by Na2HPO4 and 7 (X = p-CH3, H, p-NO2) to ω-chloroacetophenones in CCl4 were determined by following the rates of disappearance of the α-chloro epoxide and formation of the α-chloro carbonyl product.These substituent effects at 130 deg C were correlated with ?+ constants, yielding ρ values of-3.5 and -0.57 for the rearrangements of 6 and 7, respectively.In nitrobenzene solvent, the kC6H5NO2/kCCl4 for 6 was 180 and for 7 was 1740, the latter solvent effect attributed to nucleophilic solvent participation.It was concluded that these thermal rearrangements of 6 and 7 occur by disrotatory Cβ-O bond heterolysis to yield the corresponding α-keto carbonium-chloride ion pairs.
- McDonald, Richard N.,Cousins, Raymond C.
-
p. 2976 - 2984
(2007/10/02)
-