- Cu(i) catalysed annulation of isothiocyanates/isocyanates with 2-iodo-sulfonamides: Synthesis of benzodithiazines, benzothiadiazinones, benzothiazinylidene-anilines and benzothiazolylidene-anilines
-
An efficient Cu(i)-catalysed cyclisation reaction of 2-iodobenzene sulfonamides with aryl-isothiocyanates and isocyanates that affords functionalised benzodithiazines and benzothiadiazinones, respectively, has been developed. Thus, in the reaction with ar
- Sandeep,Siva Reddy, Alla,Kumara Swamy
-
-
Read Online
- A Mild Heteroatom (O -, N -, and S -) Methylation Protocol Using Trimethyl Phosphate (TMP)-Ca(OH) 2Combination
-
A mild heteroatom methylation protocol using trimethyl phosphate (TMP)-Ca(OH)2combination has been developed, which proceeds in DMF, or water, or under neat conditions, at 80 °C or at room temperature. A series of O-, N-, and S-nucleophiles, including phenols, sulfonamides, N-heterocycles, such as 9H-carbazole, indole derivatives, and 1,8-naphthalimide, and aryl/alkyl thiols, are suitable substrates for this protocol. The high efficiency, operational simplicity, scalability, cost-efficiency, and environmentally friendly nature of this protocol make it an attractive alternative to the conventional base-promoted heteroatom methylation procedures.
- Tang, Yu,Yu, Biao
-
-
- Transition-Metal-Free and Visible-Light-Mediated Desulfonylation and Dehalogenation Reactions: Hantzsch Ester Anion as Electron and Hydrogen Atom Donor
-
Novel approaches for N- and O-desulfonylation under room temperature (rt) and transition-metal-free conditions have been developed. The first methodology involves the transformation of a variety of N-sulfonyl heterocycles and phenyl benzenesulfonates to the corresponding desulfonylated products in good to excellent yields using only KOtBu in dimethyl sulfoxide (DMSO) at rt. Alternately, a visible light method has been used for deprotection of N-methyl-N-arylsulfonamides with Hantzsch ester (HE) anion serving as the visible-light-absorbing reagent and electron and hydrogen atom donor to promote the desulfonylation reaction. The HE anion can be easily prepared in situ by reaction of the corresponding HE with KOtBu in DMSO at rt. Both protocols were further explored in terms of synthetic scope as well as mechanistic aspects to rationalize key features of desulfonylation processes. Furthermore, the HE anion induces reductive dehalogenation reaction of aryl halides under visible light irradiation.
- Heredia, Micaela D.,Guerra, Walter D.,Barolo, Silvia M.,Fornasier, Santiago J.,Rossi, Roberto A.,Budén, Mariá E.
-
p. 13481 - 13494
(2020/12/15)
-
- KMnO4-mediated oxidative C[sbnd]N bond cleavage of tertiary amines: Synthesis of amides and sulfonamides
-
KMnO4-mediated oxidative C[sbnd]N bond cleavage of tertiary amines producing secondary amine was introduced, which was trapped by electrophiles (acyl chloride and sulfonyl chloride) to form amides and sulfonamides. The reaction could take place at mild condition, tolerating a wide range of function groups and affording products in moderate to excellent yields.
- Zhang, Zhang,Liu, Yong-Hong,Zhang, Xi,Wang, Xi-Cun
-
p. 2763 - 2770
(2019/04/10)
-
- Photo-Fries rearrangement of N-arylsulfonamides to aminoaryl sulfone derivatives
-
Photochemical reaction of variously substituted p-toluenesulfonanilides was studied. The reaction gives rearranged products, o- and p-amino-substituted diaryl sulfones with the combined yields of 38-72%: the p-isomer is more favored over the o-isomer with the selectivity ratio of 1.1-4.3 depending on the substituents. N-Alkylation of the sulfonanilides increases the yields of the rearranged products, and e-withdrawing substituents on the N-phenyl ring does not lower the yields drastically. This study provides simple methodology for the synthesis of o- and p-aminoaryl sulfones which are otherwise not easily accessible.
- Park, Kwanghee Koh,Lee, Jin Joo,Ryu, Jaegyung
-
p. 7651 - 7659
(2007/10/03)
-
- Unsymmetrical 4,6-diamino-2-methyl-5-nitropyrimidine synthesis via 4,6-bis(tosylates)
-
Chlorides have traditionally been used as leaving groups for the introduction of 4- and 6-heteroatomic substituents onto pyrimidines. Use of 4,6-dichloro-2-methyl-5-nitropyrimidine allows the sequential introduction of different 4- and 6-heteroatomic substituents onto this core; however, this reagent is highly hazardous to handle. We have found that the analogous 4,6-bis(tosylate) offers a less hazardous substance which undergoes the same nucleophilic aromatic substitution chemistry as the dichloride, including sequential introduction of different nucleophiles.
- Cain, Gary A.,Beck, James P.
-
p. 439 - 446
(2007/10/03)
-
- New N- and O-arylations with phenylboronic acids and cupric acetate
-
A new method of arylating N-H and O-H containing compounds at room temperature with phenylboronic acids and cupric acetate in the presence of a tertiary amine promoter is described. Substrates include phenols, amines, anilines, amides, imides, ureas, carbamates, and sulfonamides.
- Chan, Dominic M. T.,Monaco, Kevin L.,Wang, Ru-Ping,Winters, Michael P.
-
p. 2933 - 2936
(2007/10/03)
-