10.14233/ajchem.2014.16244
The study focuses on the development of a novel catalytic enantioselective method for the synthesis of chiral organoboronates, which are valuable precursors for the preparation of enantio-enriched compounds. The researchers synthesized a novel compound, 1-[2-{(1R,2S)-2-(chloromethyl)cyclopropyl]ethyl}-4-methoxybenzene, through a cyclopropanation reaction using boronate complexes as nucleophiles. Key chemicals used in the study include N,N-diisopropylcarbamoyl chloride, 3-(4-methoxyphenyl)-1-propanol, n-butyl lithium (n-BuLi), allylboronic acid pinacol ester, (-) sparteine, N,N,N,N-tetramethyl-ethylenediamine (TMEDA), 1,3-bis(trifluoromethyl)-5-bromobenzene, N-chlorosuccinimide (NCS), and trichloroisocyanuric acid (TCCA). These chemicals served various purposes, such as reactants, catalysts, and reagents in the synthesis process, with the aim of achieving high yields and enantioselectivity in the production of the target chiral compound. The study also investigated the effects of temperature and the choice of aryllithiums and electrophiles on the yields and stereoselectivity of the reaction.
10.1039/c0nj00716a
The research focuses on the abiotic formation of uroporphyrinogen and coproporphyrinogen from acyclic reactants, which are key precursors in the biosynthesis of tetrapyrrole macrocycles like porphyrins. These macrocycles are essential in various bioenergetic processes and are considered crucial for the origin of life. The study aimed to identify plausible prebiotic routes for forming these macrocycles, particularly addressing the challenge of forming the pyrrole precursor, porphobilinogen (PBG). The researchers successfully demonstrated a structure-directed route where d-aminolevulinic acid (ALA) reacts with 5-methoxy-3-(methoxyacetyl)levulinic acid (1-AcOH) under anaerobic conditions in water at moderate temperatures and pH levels, yielding uroporphyrinogen. This process bypasses the need for PBG, a significant hurdle in prebiotic chemistry, and suggests a possible prebiotic pathway for the formation of tetrapyrrole macrocycles. The study also showed that a different precursor could lead to the formation of coproporphyrinogen without the intermediacy of uroporphyrinogen. The chemicals used in this process include ALA, 1-AcOH, and their decarboxy analogues, which under specific conditions, resulted in the formation of uroporphyrinogen and coproporphyrinogen, respectively.
10.1021/jo401283x
The study describes a novel protocol for synthesizing 2-halomethylene-3-oxoketoxime derivatives from isoxazoline N-oxide derivatives using N-bromosuccinimide (NBS) and trichloroisocyanuric acid (TCCA) as halogenating agents. The researchers discovered that the keto functionality of the 3-ketoximes could be selectively reduced by lithium aluminum hydride to produce a unique type of Baylis?Hillman oxime, which could undergo N?O coupling to form new isoxazoline N-oxide derivatives. The study explores the optimization of reaction conditions and evaluates the scope of the methodology with various substituted isoxazoline N-oxides. The results show that the reaction yields are influenced by the type of halogenating agent and the substituents on the phenyl ring. The study also demonstrates the potential of these 2-halomethylene-3-oxoketoximes as precursors for pharmaceutically active compounds and natural products.
O, 
Xn, 
N
