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β-Fluorinated vinamidinium salts ( 1 ) readily reacted with a series of Grignard reagents in tetrahydrofuran, followed by the action of reducing agents at room temperature, to produce stereospecifically the corresponding fluorinated allylamines ( 4 and 5 ) in good to excellent yields.

β-Trifluoromethyl vinamidinium salt 1 reacted cleanly with a variety of Grignard reagents 2 in tetrahydrofuran under reflux for 3 h to produce a mixture of diastereoisomers ( dl and meso ) of the corresponding difluoromethylene compounds 3 in good to excellent yields.

β-Fluorovinamidinium salt ( 1 ) reacted cleanly with a variety of Grignard reagents in tetrahydrofuran at room temperature, followed by acid workup, to produce the corresponding (Z)-α-fluoro-α,β-unsaturated aldehydes ( 3 ) in good to excellent yields.

The preparation of novel 2-(arylsulfonyl)vinamidinium salts is described. The reactions of these materials with amidines, hydrazine, hydroxylamine, sodium borohydride, and Grignard Reagents are presented along with an evaluation of their chemical behavior as compared to the 2-arylvinamidinium salts

β-Fluorovinamidinium salt ( 1 ) reacted cleanly with a variety of Grignard reagents in tetrahydrofuran at room temperature, followed by acid workup, to produce the corresponding (Z)-α-fluoro-α,β-unsaturated aldehydes ( 3 ) in good to excellent yields.

The preparation of novel 2-(arylsulfonyl)vinamidinium salts is described. The reactions of these materials with amidines, hydrazine, hydroxylamine, sodium borohydride, and Grignard Reagents are presented along with an evaluation of their chemical behavior as compared to the 2-arylvinamidinium salts

β-Dimethylaminomethylenation: N,N-dimethyl-N′-p- tolylformamidine intermediate: [3-(Dimethylamino)-2-azaprop-2-en-1-ylidene]dimethylammonium chloride product: N,N-dimethyl-N′-p-tolylformamidine Keywords: aminomethylenation; decarboxylation; ring opening reactions; N,N-dimethylformamide; dioxane; Gold's reagent; cyanuric chloride

[20353-93-9] C6H14ClN3 (MW 163.65) InChI = 1S/C6H14N3.ClH/c1-8(2)5-7-6-9(3)4;/h5-6H,1-4H3;1H/q+1;/p-1 InChIKey = DEIBXAPEZDJDRC-UHFFFAOYSA-M (β-dimethylaminomethylenating agent for ketones and amines;2 yields enamino derivatives of esters and lactones;3 converts Grignard reagents to aldehydes4) Alternate Name: Gold's reagent. Physical Data: mp 100–102 °C. Solubility: sol water, chloroform; insol nonpolar organic solvents. Form Supplied in: tan to dark brown solid; commercially available. Preparative Methods: 5 a 1 L, one-necked, round-bottomed flask is equipped with a Claisen adapter, mechanical stirrer, reflux condenser, and mineral oil bubbler. The flask is charged with cyanuric chloride (73.8 g, 0.4 mol) (Caution: cyanuric chloride is a lachrymator and causes burns on contact with the skin), N,N-Dimethylformamide (175.4 g, 2.4 mol) and 1,4-dioxane (100 mL). The resulting solution is stirred and heated at 85 °C for 2–3 h while a considerable amount of carbon dioxide is evolved. When gas evolution is minimal, the reaction mixture is allowed to cool to room temperature; the product rapidly solidifies (eq 1). The flask which contains the solid product is connected to an isopropyl alcohol/dry ice trap and the solvent is removed by evacuating the system to approximately 0.05 mmHg. The crude product weighs 186–187 g (95% yield). Another method of isolating the product is by rapid filtration and washing with acetone. (1) Analysis of Reagent Purity: 1H NMR (CDCl3) δ 3.27 (s, 6H, two CH3), 3.43 (s, 6H, two CH3), 9.57 (s, 2H, CHN). Handling, Storage, and Precautions: Gold's reagent is very hygroscopic and should be handled under a moisture-free environment. If kept dry, it has a substantial shelf-life. Store in desiccator over anhydrous calcium sulfate.

A series of esters and nitrotoluenes were reacted with Gold's reagent under basic conditions and were found to produce the corresponding dimethylamino methylenenated product in both cases.

A variety of organometallic reagents have been found to undergo regioselective reaction with 1-aryl-vinamidinium salts and 3-aryl-3-chloropropeniminium salts. The products of such reactions were found to be α,β-unsaturated ketones and chlorovinyl amines, respectively.

A series of organometallic reagents have been added to a 2-arylsubstituted vinamidinium perchlorate. The resulting reaction mixture was treated with borane or diisobutylaluminum hydride solution to produce a series of 3-substituted-2-aryl-N,N-dimethyl allylic amines. The overall one-pot procedure constitutes a convenient synthesis of 2,3-disubstituted allylic amines.

A series of ortho aminobenzoic acids were treated with Gold's reagent. In each case a 4-hydroxyquinazoline was produced. The resulting transformation constitutes the use of Gold's reagent as a two atom lynch pin.

A variety of 2-aryl-N, N-dimethylallylic amines have been reacted with butyllithium and t-butyllithium to produce the corresponding 3-butyl and 3-t-butyl substituted 2-aryl-propenes. This procedure represents a convenient and clean method for the synthesis of α-substituted styrenes and related substances.

We recently reported1 that [3-(Dimethylamino)-2-azaprop-2-en-1-ylidene] dimethylammonium chloride2 (1) could be reacted with anions derived from ketones or amides to produce enaminones or acylamidines, respectively.

We recently reported1 that “Gold's reagent” (1) is an effective material for the conversion of aryl methyl ketones to the corresponding aryl 8-dimethylaminovinyl ketones.

The reaction of simple iminium salts, such as the Eschenmoser reagent (1) with Grignard and lithium reagents has been recently described1.

A variety of organometallic reagents have been found to undergo regioselective reaction with 1-aryl-vinamidinium salts and 3-aryl-3-chloropropeniminium salts. The products of such reactions were found to be α,β-unsaturated ketones and chlorovinyl amines, respectively.

A variety of 2-aryl-N, N-dimethylallylic amines have been reacted with butyllithium and t-butyllithium to produce the corresponding 3-butyl and 3-t-butyl substituted 2-aryl-propenes. This procedure represents a convenient and clean method for the synthesis of α-substituted styrenes and related substances.

The reactions of an unsubstituted vinamidinium salt with organometallic reagents, borane, and DIBAL-H are described. The products of these reactions were unsaturated aldehydes, and allylic amines. The reaction conditions and possible mechanistic implications are also discussed.

A series of o-phenylenediamines and o-aminophenols have been reacted with Gold's reagent to yield benzimidazoles and benzoxazoles, respectively. Additionally, o-hydroxyacetophenone and anthranilamide, when reacted with Gold's reagent, were found to produce chromone and 3H-quinazoline-4-one, respectively. These transformations represent the use of Gold's reagent as a one atom lynch pin.