33234-57-0Relevant academic research and scientific papers
Metal-Free Directed C?H Borylation of Pyrroles
Wang, Zheng-Jun,Chen, Xiangyang,Wu, Lei,Wong, Jonathan J.,Liang, Yong,Zhao, Yue,Houk, Kendall N.,Shi, Zhuangzhi
supporting information, p. 8500 - 8504 (2021/03/16)
Robust strategies to enable the rapid construction of complex organoboronates in selective, practical, low-cost, and environmentally friendly modes remain conspicuously underdeveloped. Here, we develop a general strategy for the site-selective C?H borylation of pyrroles by using only BBr3 directed by pivaloyl groups, avoiding the use of any metal. The site-selectivity is generally dominated by chelation and electronic effects, thus forming diverse C2-borylated pyrroles against the steric effect. The formed products can readily engage in downstream transformations, enabling a step-economic process to access drugs such as Lipitor. DFT calculations (wB97X-D) demonstrate the preferred positional selectivity of this reaction.
Direct β-C(sp3)-H Functionalization of Aliphatic Amines to α,β-Unsaturated Imines, Aldehydes, and Chromenes
Mandal, Sumana,Mahato, Sujit,Jana, Chandan K.
, p. 3762 - 3765 (2015/08/18)
A metal-free method for direct β-C(sp3)-H functionalization of aliphatic amine was developed. The method is based on a reaction that yields enamine directly from the corresponding aliphatic amine, which otherwise requires the aid of metallic reagent and/or external oxidant. The reaction is operationally simple, general, and highly efficient in functionalizing both cyclic and acyclic amines. Structurally diverse unsaturated imines were obtained from N-heterocycles, while acyclic amines provided 2-alkyl cinnamaldehyde and benzopyran derivatives with excellent E/Z-selectivity.
Antimalarial activity of natural and synthetic prodiginines
Papireddy, Kancharla,Smilkstein, Martin,Kelly, Jane Xu,Shweta,Salem, Shaimaa M.,Alhamadsheh, Mamoun,Haynes, Stuart W.,Challis, Gregory L.,Reynolds, Kevin A.
experimental part, p. 5296 - 5306 (2011/10/02)
Prodiginines are a family of linear and cyclic oligopyrrole red-pigmented compounds. Herein we describe the in vitro antimalarial activity of four natural (IC50 = 1.7-8.0 nM) and three sets of synthetic prodiginines against Plasmodium falciparum. Set 1 compounds replaced the terminal nonalkylated pyrrole ring of natural prodiginines and had diminished activity (IC 50 > 2920 nM). Set 2 and set 3 prodiginines were monosubstituted or disubstituted at either the 3 or 5 position of the right-hand terminal pyrrole, respectively. Potent in vitro activity (IC50 = 0.9-16.0 nM) was observed using alkyl or aryl substituents. Metacycloprodiginine and more potent synthetic analogues were evaluated in a P. yoelii murine patent infection using oral administration. Each analogue reduced parasitemia by more than 90% after 25 (mg/kg)/day dosing and in some cases provided a cure. The most favorable profile was 92% parasite reduction at 5 (mg/kg)/day, and 100% reduction at 25 (mg/kg)/day without any evident weight loses or clinical overt toxicity.
The Direct Alkylation of π-Rich, Acid-Sensitive Heterocyclic Compounds via Essentially Free Carbocations
Darbeau, Ron W.,White, Emil H.
, p. 8091 - 8094 (2007/10/03)
Alkylation of π-rich heteroaromatics such as pyrroles and furans by the standard Friedel-Crafts approach is impractical because the acid catalysts employed (Bronsted or Lewis) induce polyalkylation, ring opening, and polymerization. The present study describes the facile benzylation of π-excessive heteroaromatics using the nitrosoamide approach, which generates nitrogen-separated carbocation-counterion ion-pairs as the alkylating agent with no catalyst being required. N-Nitrosoamides are favorable sources of carbocations because of the following variables: mildness of the conditions required to generate cations, high reactivity of the unsolvated carbocations formed, solubility of the precursors in a wide range of solvents, homogeneity of the reactions, wide range of decomposition temperatures possible, straightforward chemistry, and excellent product balance. The majority of the cations that are generated in pyrrole (80%) are intercepted by the solvent, and only 20% are intercepted by the counterion; this result provides support for the intermediacy of nitrogen-separated ion-pairs in deamination. A nucleophilicity scale is presented for reactions of selected nucleophiles with essentially free carbocations.
A NEW AND EFFECTIVE AMINOMETHYLATION BY THE USE OF N-(p-TOLUENESULFONYLMETHYL)-p-TOLUENESULFONAMIDE AS AN EQUIVALENT OF METHANIMINE. A CONVENIENT PREPARATION OF PYRROLE COMPOUNDS
Kinoshita, Hideki,Inomata, Katsuhiko,Hayashi, Masatoshi,Kondoh, Takeshi,Kotake, Hiroshi
, p. 1033 - 1036 (2007/10/02)
Readily available N-(p-toluenesulfonylmethyl)-p-toluenesulfonamide was treated with base to generate N-methylene-p-toluenesulfonamide which reacted with a variety of nucleophiles forming the corresponding N-tosyl-aminomethylated compounds in good yields.Furthermore, the N-tosyl-aminomethylated acetals thus obtained were converted into the corresponding N-tosylpyrroles with the aid of acid catalyst in excellent yields.
Synthesis of Alkylpyrroles by the Sodium Borohydride Reduction of Acylpyrroles
Greenhouse, Robert,Ramirez, Coral,Muchowski, Joseph M.
, p. 2961 - 2965 (2007/10/02)
N-Unsubstituted alkylpyrroles are obtained by the reduction of the corresponding acylpyrroles with sodium borohydride in boiling 2-propanol.This reaction was demonstrated to proceed via the pyrrolylalkylcarbinol and was extended to the synthesis of a branched chain alkylpyrrole 25 from the tertiary alcohol 24.
Benzyl pyrrolyl methyl carboxylate insecticides and acaricides
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, (2008/06/13)
Carboxylic acid esters of the formula (I), STR1 wherein X is a hydrogen atom, or a C1 -C3 alkyl or a C1 -C3 alkoxyl group or a halogen atom linked to the meta or para position and R1 is a group of the
