Benchtop Nickel Catalysis Invigorated by Electron-Deficient Diene Ligands.

ConspectusDue to the rarity of precious metals like palladium, nickel catalysis is becoming an increasingly important player in organic synthesis, especially for the formation of bonds with sp-hybridized carbon centers. Traditionally, catalytic processes involving active Ni(0) species have relied on Ni(COD) or in situ reduction of Ni(II) salts. However, Ni(COD) is an air- and temperature-sensitive material that requires use in an inert-atmosphere glovebox, and in situ reduction protocols of Ni(II) salts using metallic or organometallic reductants add additional complications to reaction development.

Ligand-Promoted Iron-Catalyzed Nitrene Transfer for the Synthesis of Hydrazines and Triazanes through N-Amidation of Arylamines.

Herein, we report that bulky alkylphosphines such as PtBu can switch the roles from actor to spectator ligands to promote the FeCl -catalyzed N-amidation reaction of arylamines with dioxazolones, giving hydrazides in high efficiency and chemoselectivity. Mechanistic studies indicated that the phosphine ligands could facilitate the decarboxylation of dioxazolones on the Fe center, and the hydrogen bonding interactions between the arylamines and the ligands on Fe nitrenoid intermediates might play a role in modulating the delicate interplay between the phosphine ligand, arylamine, and acyl nitrene N, favoring N-N coupling over N-P coupling. The new ligand-promoted N-amidation protocols offer a convenient way to access various challenging triazane compounds via double or sequential N-amidation of primary arylamines.

Clinical and whole exome sequencing findings in children from Yunnan Yi minority ethnic group with retinitis pigmentosa: two case reports.

Background: Retinitis pigmentosa is a group of rare hereditary retinal dystrophy diseases that lead to difficulty seeing at night, progressive loss of peripheral field vision (tunnel vision), and eventual loss of central vision. However, a genetic cause cannot be determined in approximately 60% of cases.

Case Presentation: Two non-consanguineous Yi minority ethnic group families who have a 6.

Clinical and whole-exome sequencing findings in two siblings from Hani ethnic minority with congenital glycosylation disorders.

Background: PMM2-CDG, is the most common N-linked glycosylation disorder and subtype among all CDG syndromes, which are a series of genetic disorders involving the synthesis and attachment of glycoproteins and glycolipid glycans. The mutations of PMM2-CDG might lead to the loss of PMM2, which is responsible for the conversion of mannose 6- phosphate into mannose 1-phosphate. Most patients with PMM2-CDG have central nervous system involvement, abnormal coagulation, and hepatopathy.

A novel variant in MITF in a child from Yunnan-Guizhou Plateau with autosomal dominant inheritance of nonsyndromic hearing loss: A case report.

Deafness and hearing loss may have functional, economic, social and emotional impacts on humans, including the ability of an individual to communicate with others, feelings of isolation and frustration, and health sector costs. The World Health Organization reported that there are 32 million children worldwide with hearing loss. In order to investigate genetic mutations in children of 26 nationalities with hearing loss in Yunnan, Sanger sequencing was employed to screen for mutations in four of the most common pathological genes, including gap junction protein β2 and 3, solute carrier family 26 member 4 and mitochondrial DNA.

[Two New Abietane Type Diterpenes from Pinecones of Pinus griffithii].

Objective: To study the chemical constituents from the pinecones of Pinus griffithii.

Methods: The constituents were separated and purified with chromatographic methods,and spectroscopic analysis were employed for structural elucidation.

Results: Two new abietane type diterpenes and seven known compounds were isolated from the pinecones of Pinus griffithii,and were identified as 15-hydroxy-7α-methoxy-abiet-8,11,13-trien-18-oic acid( 1),7α,13-dihydroxy-podocarpane-8,11,13-trien-18-oic acid( 2),7,12,13,15-tetrahydroxy-abiet-8( 14)-en-18-oic acid( 3),7β,15-dihydroxy-abiet-8,11,13-trien-18-oic acid( 4),18-norabiet-8,11,13-trien-4,7,15-triol( 5),15-hydroxy-abiet-8,11,13-trien-18-oic acid( 6),7α-hydroxy-15-methoxy-abiet-8,11,13-trien-18-oic acid( 7),7α-hydroxypodocarpen-8( 14)-en-13-one-18-oic acid( 8), oleanolic acid( 9).