3-Cyclohexene-1 -carboxamide

PIFA easily converts succinic acid derivatives (32) to -alanine derivatives (33). Limited use of PIFA (1 equiv.) allows the rearrangement of 3-cyclohexene-1-carboxamide (34) without oxidation of the double bond, as shown in Scheme 12. Cyclohexanone is obtained by the PIFA oxidation of 1-cyclohex-enecarboxamide (35). Selective oxidation of the primary amide (36) occurs without effect on secondary or tertiary amides in the same molecule. The rearrangement of the cyclopropane derivative (37) accompanies the ring cleavage to give the -alanine derivative (38) after treatment with benzyloxycarbonyl chloride. ... 

Other methods for the preparation of cyclohexanecarboxaldehyde include the catalytic hydrogenation of 3-cyclohexene-1-carboxaldehyde, available from the Diels-Alder reaction of butadiene and acrolein, the reduction of cyclohexanecarbonyl chloride by lithium tri-tcrt-butoxy-aluminum hydride,the reduction of iV,A -dimethylcyclohexane-carboxamide with lithium diethoxyaluminum hydride, and the oxidation of the methane-sulfonate of cyclohexylmethanol with dimethyl sulfoxide. The hydrolysis, with simultaneous decarboxylation and rearrangement, of glycidic esters derived from cyclohexanone gives cyclohexanecarboxaldehyde. 

Although iodine(III) reagents attack double bonds, the rearrangement of the amide group is, at least in some cases, more rapid than electrophilic attack on alkenes. Thus 3-cyclohexene-l-carboxamide rearranges smoothly to the corresponding amine as long as only one equivalent of [1,1-bis(trifluoroacetoxy)iodojbenzene is used. 

Rowland et al. prepared a low-spin Fe(III) complex 24 from N, N-bis(2-pyridylmethyl) amine-N-ethyl-2-pyridine-2-carboxamide 23 (Scheme 3.31) [125]. When cyclohexene la reacted with complex 24 and a large excess of H202, among the oxidation products epoxide 4a predominated (TON 17). 

The best result using aldehyde/oxygen was reported recently by Qi et al. [53] using novel Ru(HL)(L)C12 (HL is N-2 chlorophenyl-2-pyridine-carboxamide) complexes and isobutyraldehyde/oxygen for the epoxidation of cycbc alkenes. The turnover frequencies (TOFs) in this system were as high as 350 h 1 for cyclohexene, with a selectivity towards the epoxide of 87% (see Eq. 12). 

C7H10 2-norbornene 498-66-8 25.00 0.9500 1 11383 C7H12N20 trans-2-amino-4-cyclohexene-1-carboxamide 27411-24- 25.00 1.0278 2... 

Fig. 1.9 Competitive hydrogenation of (a) 3-cyclohexene-l-methanol and cyclohexene (b) N-methyl-3-cyclohexene-l carboxamide and cyclohexene using various Pd catalysts (Reprinted with permission from Ref [22b], Kaneda group,...

A solution of 500 mg A-methylcyclohexane-c -l,2-dicarboxyimide in 25 mL CH3CN was purged with nitrogen and irradiated for 7 h. After removal of the solvent, the residue was separated by column chromatography to afford 298 mg of a mixture of starting material and lV-methylcyclohexane-tran5-l,2-dicarboxyimide, 88 mg N-methylcyclohexane-l,l-dicarboxyimide (43%, colorless crystal, m.p. 96-97°C), and 14 mg A-formyl-A-methyl-1 -cyclohexene-1 -carboxamide (7%). 

J. A. Klun et al.. Comparative resistance of Anopheles albimanus and Aedes aegypti to A,A-diethyl-3-methylbenzamide (Deet) and 2-methylpiperidinyl-3-cyclohexen-l-carboxamide (AI3-37220) in laboratory human-volunteer repellent assays, J. Med. EntomoL, 41, 418, 2004. 

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