ISSN:
0009-2940
Keywords:
Aminobenzannulation with isocyanides
;
1,4-Diaminonaphthalines
;
Alkynylcarbene complexes
;
β-Aminovinylcarbene complexes
;
Dienylketenimine complexes
;
4-Amino-1-chroma-1,3-dienes
;
Chromium complexes
;
Chemistry
;
Inorganic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
Organic Syntheses via Transition Metal Complexes, 64[1]. - 1,4-Diaminonaphthalines via Ketenimine Complexes from (β-Aminovinylcarbene)chromium Complexes and IsocyanidesThe thermal reaction of (dienylcarbene)chromium complexes (= 1-chroma-1,3,5-trienes) with isocyanides provides a mild and regiospecific access to aromatic amines. Thus, 1,4-diamino-2-ethoxynaphthalines 6a-d [1-NHc-C6H11; 4-NRR1 = NMe2 (a) (S)-2-hydroxymethylpyrrolidinyl (b) (1R,2S)-2-methylamino-1-phenyl-1-propanol (c), NtBuMe (d)] are obtained by the cyclization of (E)-(β-aminostyrylcarbene)chromium complexes (CO)5Cr=C(OEt)CH=C(NRR1)C6H5 [(E)-3a-d] with cyclohexyl isocyanide (4) at 90°C in 72-85%. The aminocarbene complexes (E)-3a-d are accessible with high stereoselectivity [〉95% (E) configuration] and chemical yields of 91-96% by the addition of secondary amines HNRR1 2a-d to the (1-alkoxy-3-phenylpropynylidene)chromium complex (CO)5Cr=C(OEt)C≡CC6H5 (1). 3 and 4 give initially mono- and bis(isocyanide) complexes, e.g. (E)-8a and (E)-9a, and subsequently dienylketenimine complexes by the insertion of 4 into the M=C bond of 3. Dienylketenimine complexes are key intermediates in the formation of 6.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/cber.19931260818
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