Electro-reductive carboxylation of acyclic C(sp^(3))–C(sp^(3))bonds in aromatic hydrocarbons with CO_(2)

Despite the recent advances in the selective functionalization of C–C bonds in specific substrates,cleavage and functionalization of C–C bonds in acyclic substrates,such as ethane derivatives,remains challenging.In contrast to the well-developed functionalization of one carbon fragment after C–C bond cleavage,herein,we report a novel electro-reductive carboxylation of C(sp^(3))–C(sp^(3))bond in multi-aryl ethanes with carbon dioxide(CO_(2))by utilizing both carbon fragments.Thus,this reaction exhibits an atom-,step-economic approach for the synthesis of carboxylic acids,fulfilling principal aspirations of organic synthesis.Moreover,this method features mild reaction conditions,broad substrate scope,and good functional group tolerance.Symmetric and asymmetric substrates bearing primary,secondary,or tertiary C(sp^(3))–C(sp^(3))bonds are all amenable to this strategy,enabling one or two structurally different carboxylic acids to be facilely constructed at the same time.Mechanistic investigations indicate that carbanions might be the key intermediates in this reaction,which could be captured by CO_(2)efficiently.

Opaque Polyploid Cells in Ishikawa Endometrial Cultures Are Capable of Forming Megamitochondria, Organelles Derived from the Adaptation of Fused Mitochondria Whose Capacity to Develop Gaseous Vacuoles Suggests CO₂Retention and Hypoxic Metabolism

Opaque polyploid cells capable of forming megamitochondria are a constant feature in colonies of Ishikawa endometrial epithelia, accounting for approximately 5% - 10% of the cells. Opaque cells appear to communicate with other opaque cells via membrane extensions and with other cells in a colony by extra-cellular vesicles. Opaque cells form first as rectangular structures, somewhat larger than surrounding monolayer cells. The cells eventually round up, remaining in the colony for 20 or more hours before detaching. The most unusual characteristic of Ishikawa opaque cells is their capacity to form mitonucleons, megamitochondria that surround aggregated chromatin. This paper reviews evidence that adaptations resulting in megamitochondria include a loss of the capacity for oxidative phosphorylation leaving the adapted megamitochondria reliant on metabolism such as reductive carboxylation.

Chemoselective Reduction of Fenofibric Acid to Alcohol in the Presence of Ketone by Mixed Anhydride and Sodium Borohydride

A highly efficient and facile protocol for the selective reduction of carboxylic acid of Fenofibric acid to corresponding alcohol was developed. The selective reduction was carried out by activation of carboxylic acid by mixed anhydride followed by the reaction of sodium borohydride in presence of methanol. This is the first example of chemoselective reduction of carboxylic acid to alcohol in presence of a ketone without any external catalyst or ligand in a single step. The reaction offers wide applicability for the selective carboxylic group reduction methodology. The chemoselective reduction was demonstrated by the reduction of Fenofibric acid, an active metabolite of the drug Fenofibrate, to corresponding alcohol in excellent selectivity, yield, and purity.

PREPARATION OF ENANTIOMERICALLY PURE SYN-4,5-DIHYDROXY CARBOXYLIC ACID LACTONES BY MICROBIAL REDUCTION

Enantiomerically pure syn-4,5-dihydroxy carboxylic acid lactones were prepared by microbial reduction of acyl lactones with resting cell of Aspergillus niger.