سد الذرائع حقيقته ونماذج من تطبيقاته المعاصرة

Today’s world is a global village. Societies affect each other far deeper and faster than ever. New problems are sprouting with every coming day. We feel that the cultural issues are the most significant ones in this context. The question is how we should deal with these problems. To us, the solution lies in the concept of Sadd al-Dharā’i‘(prevention), one of the instruments of Sharī‘ah (Islamic Law). Such is its importance as all the four schools of thought are of the same opinion about its scope. A cultural change if drives Muslims away from the objectives of Sharī‘ah, it will have to be stopped or altered to suit the objectives, but if it leads to something good without damaging the objectives of Sharī‘ah, it will be accepted. New problems are multifarious. We need to bring ijtihād into practice and solve such problems. This research article discusses the concept of Sadd al-Dharā’i‘(prevention.), its meaning, definition, and scope. It also discusses different opinions of scholars. The author of this paper, then, deliberates its use for its applications to solve the new problems being faced by the Muslims across the world.

Transition Metal-Catalyzed Borylation of Aromatics

Selective functionalization of hydrocarbons represents a long-standing challenge in the synthetic world. Transition metal-catalyzed reactions, such as transformation of C–H/ C– X bond to C–B bond has emerged as potent tool towards this goal during the last few decades. Especially the Ir-catalyzed aromatic C-H activation/borylaytion provides unique selectivity which is complemantary to those found in the traditional synthetic routes. Sterically governed regioselective control in this new synthetic tool allows the synthesis of (hetero)aromatic compounds which are difficult to access by the conventional routes. In the current work, we have utilized this methodology to gain facile access to new aromatic building blocks with better atom & step economy. One study presents the synthesis of hydroxybenzoates. Hydroxybenzoates are widely used as preservatives and antiseptics in the food and pharmaceutical industry. However, strategies focusing on the direct synthesis of 2,6- and 2,3-disubstituted hydroxybenzoates are lacking in literature. Herein we report an efficient protocol employing iridium-catalyzed C–H borylation/oxidation of commercially available benzoic acid/ester substrates. This route provides facile access to halogen decorated para-/meta-hydroxybenzoates as the synthesis of akin compounds is laborious by traditional approaches. Second project targets the synthesis of boscalid analogs. Boscalid is an extensively used fungicide for crop protection. Traditional routes of boscalid synthesis involve precursors that need pre-functionalization of arenes, which affects the step economy and overall efficiency. The aim of this study is to develop boscalid analogues from readily available hydrocarbon feedstock without pre-functionalization. Sequential Ir-catalyzed C–H borylation of arenes and Suzuki coupling provide biphenyl amines which on amidation produce boscalid analogues in good yield. Synthesized compounds are further evaluated by molecular docking to gain insight into the binding pocket of protein. The In-vitro studies of the analogs are carried out against Fusarium moniliforme and few of the synthesized compounds provided superior inhibition on potato dextrose agar (PDA) plates. Next, Ir-catalyzed C-H borylation of CF3 substituted pyridines is reported. The versatility of the methodology is demonstrated by the use of various substitution patterns in the substrate molecule. Based on the steric evaluation, selective positions of CF3 substituted pyridines are functionalized. Several functional groups like halo, ester, methoxy and amino are compatible with this methodology. Chiral boronic esters are indispensable building blocks owing to their versatile transformations and immense applications in medicinal and material chemistry. Herein, we also disclose Pd-catalyzed chiral borylation of aryl halides, whereby numerous substrates bearing broad range of functional groups are found to be compatible for the developed approach. Aryl/hetero aryl chiral boronic esters are obtained in moderate to excellent yield. The resulting chiral boronic esters can serve as significant precursors in asymmetric synthesis.