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.

Directed, nickel-catalyzed 1,2-alkylsulfenylation of alkenyl carbonyl compounds.

We report a regioselective, nickel-catalyzed -1,2-carbosulfenylation of non-conjugated alkenyl carbonyl compounds with alkyl/arylzinc nucleophiles and tailored N-S electrophiles. This method allows the simultaneous installation of a variety of C(sp) and S(Ar) (or Se(Ar)) groups onto unactivated alkenes, which complements previously developed 1,2-carbosulfenylation methodology in which only C(sp) nucleophiles are compatible. A bidentate directing auxiliary controls regioselectivity, promotes high -stereoselectivity with a variety of - and -internal alkenes, and enables the use of an array of electrophilic sulfenyl (and seleno) electrophiles.

Next generation sequencing of RB1gene for the molecular diagnosis of ethnic minority with retinoblastoma in Yunnan.

Background: Retinoblastoma is a rare intraocular malignancy and typically initiated by inactivating biallelic mutations of RB1 gene. Each year, ~ 8000 children worldwide are diagnosed for retinoblastoma. In high-income countries, patient survival is over 95% while low-income countries is ~ 30%.

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.

Characteristics of olfactory ensheathing cells and microarray analysis in Tupaia belangeri (Wagner, 1841).

Tree shrews are most closely related to the primates and so possess a number of advantages in experimental studies; they have been used as an animal model in bacterial and virus infection, cancer, endocrine system disease, and certain nervous system diseases. Their olfactory ensheathing cells (OECs) are able to release several cytokines to promote neuronal survival, regeneration and remyelination. The present study used western blot analysis to identify antibody specificity in protein extracts from whole tree shrew brains to identify the specificity of p75 nerve growth factor receptor (NGFR) derived from rabbits (75 kDa).

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).

[Chemical Constituents from Pueraria alopecuroides Ratten].

Objective: To study the chemical constituents from the ratten of Pueraria alopecuroide.

Methods: Column chromatography techniques were used for compounds separation. And their structures were elucidated by physico-chemical properties and means of spectral analysis.