Chemistry can be defined as the study of matter and the changes it undergoes. You¡¯ll sometimes hear it called the central science because it is the connection between physics and all the other sciences, starting with biology. 536-66-3, Name is 4-Isopropylbenzoic acid, molecular formula is , belongs to Benzisoxazole compound. In a document, author is Huang Hao, SDS of cas: 536-66-3.
Copper-Catalyzed Enantioselective Aminoboration of Styrenes with 1,2-Benzisoxazole as Nitrogen Source
Organoboron compounds are important intermediates in organic synthesis because of their high utilities for C-C and C-X bond formations. Transition metal-catalyzed borylative difunctionalization of alkenes, which can simultaneously introduce C-B, C-C or C-X bonds, could directly construct highly functionalized organoboron in one step. Among these reactions, copper catalyzed enantioselective aminoboration of styrenes is an efficient approach to generate enantioriched beta-aminoboronate which is a class of useful chiral compounds. In this work, employing styrenes as substrates, 1,2-berrzisoxazole as an electrophilic primary amine source, bis(pinacolato)diboron (B(2)pin(2)) as boron source and LiOCH3 as base, an enantioselective Cu-catalyzed aminoboration of styrenes by using a chiral sulfoxide-phosphine (SOP) ligand was developed, and a board range of chiral beta-aminoalkylboranes, which could be readily converted to a class of valuable beta-hydroxylalkylamines, were accessed with high yields and ee values. A general procedure for this aminoboration of styrenes is described in the following: in a glove box, CuI (0.05 mmol), chiral sulfoxide phosphine ligand L1 (0.06 mmol), and 2 mL of anhydrous tetrahvdrofuran were added into a flame-dried tube. The resulting mixture was stirred at room temperature for 30 min. then bis(pinacolato)diboron (B(2)pin(2)) (0.75 mmol), LiOCH3 (1.25 mmol), styrene 1 (0.5 nunol), 1,2-benzisoxazole (0.75 mmol) and another 2 mL of THE were added into the reaction system in sequence. The reaction tube was removed out from the glove box and stirred at 20 degrees C for 12 h. After the reaction was finished, the NMR yield was firstly determined with dimethyl terephthalate (9.7 mg, 0.05 mmol) as internal standard, then, the crude product was recovered and purified with a preparative TLC which was alkalized with triethylamine to give the desired beta-aminoboronates in moderate to good yields (47%similar to 84%) and enantioselectivities (81%similar to 99%). To demonstrate the utility of this reaction, beta-boronate primary amine could be easily obtained by removing the Schiff base group of beta-aminoboronate 3 under the methanol solution of hydroxylamine hydrochloride, which could be further oxidized to give corresponding chiral beta-amino alcohol in moderate yield (48%).
Sometimes chemists are able to propose two or more mechanisms that are consistent with the available data. If a proposed mechanism predicts the wrong experimental rate law, however, the mechanism must be incorrect.Welcome to check out more blogs about 536-66-3, in my other articles. SDS of cas: 536-66-3.
Reference:
Benzisoxazole – Wikipedia,
,Benzisoxazole – an overview | ScienceDirect Topics