Halo sulfonyl derivatives

Trialkylboranes react rapidly and in high yields with a-halo ketones,a-halo esters, a-halo nitriles, and a-halo sulfonyl derivatives (sulfones, sulfonic esters, sulfonamides) in the presence of a base to give, respectively, alkylated ketones, esters, nitriles, and sulfonyl derivatives. Potassium tert-butoxide is often a suitable base, but potassium 2,6-di-tert-butylphenoxide at 0°C in THF gives better results in most cases, possibly because the large bulk of the two tert-buXy groups prevents the base from coordinating with the R3B. The trialkylboranes are prepared by treatment of 3 mol of an alkene with 1 mol of BH3 (15-16). With appropriate boranes, the R group transferred to a-halo ketones, nitriles, and esters can be vinylic, or (for a-halo ketones and esters) aryl. " °... 

Halo furazans and -furoxans and miscellaneous derivatives (cyano-, sulfonyl-groups) 356... 

The Ar-(3-cyclopropyl-2,4-pyrimidyl)- 96a and hT-(3-cydopropyl-2,4,6-tri-azinyl)-AT-aryl sulfonyl ureas 96b (R = halo-, amino-, alkoxyalkyl and cycloalkyl X = CH, N) are useful as plant growth regulators and herbicides. At 500 g per ha the cyclopropyltriazine derivative 96 b (R = OMe, Ar = 2-carbomethoxy-phenyl) killed Abutilon species and Sivapis alba or prevented germination without affecting wheat, Eq. (37) [128]. 

The 4H NMR spectra of some methyl-,79-83 halo-,81 mercapto-,84 nitro-,84 and methoxybenzo[6]thiophenes,85 and of some sulfonic acids, sulfonyl chlorides, and sulfonate esters86 have been recorded. Two groups of workers87,88 have independently studied the 4H NMR spectra of a range of benzo[6]thiophene derivatives in an attempt to correlate the chemical shifts of the protons with the substituents. Such a correlation helps to assign structures to new benzo[6]thiophene derivatives, and it also throws light on the influence of substituents on the NMR parameters of heteroaromatic systems in general. 

Extensive work by Smiles and his collaborators and by other groups clarified the main features of the rearrangement involving nitro-, sulfonyl- and halo-substituted aromatic rings. Rearrangement of 2-amino-pyridine derivatives has also been extensively studied. Reactions involved the replacement of hetero-substituents, a C - O bond by a C - N bond (N - 0), C - S by C - N (N - S) and C - S by C - O (O - S), etc. Early work has been reviewed by Bun-nett [3] (1951) and Truce [4] (1970). 

In addition to the carbon-centered radical initiators, arenesulfonyl halides are simple and efficient functionalized initiators by introducing a variety of functional termini conjugation between the aryl and the sulfonyl groups is absent (FI-51 to FI-58 Figure 14).175 Typically, a series of monosubstituted derivatives (FI-51) are commercially available and afford hydroxyl, carboxyl, nitro, and halo groups in living... 

In primary synthesis 2-perimidinamines (660) can be prepared from the naphthalene diamine with bromocyanogen or cyanamide (Scheme 106). 2-Anilino derivatives have been obtained in reactions with aryl isothiocyanates. 2-iV,7V-Dimethylamino derivatives (662) have been obtained via the alkylated amine (661) using dimethylamino(trichloro)methane. Nucleophilic substitution by amine readily occurs in the 2-position when carrying a halo, sulfenyl, or sulfonyl substituent <81RCR816>. 

---