Copper(ii)-catalyzed and acid-promoted highly regioselective oxidation of tautomerizable C(sp)-H bonds adjacent to 3,4-dihydroisoquinolines using air (O) as a clean oxidant.

A mild, efficient and eco-friendly method for the oxidation of 1-Bn-DHIQs to 1-Bz-DHIQs without concomitant excessive oxidation of 1-Bz-DHIQs to 1-Bz-IQs is very important for the syntheses of 1-Bz-DHIQ alkaloids and analogues. In this article, we developed a novel Cu(ii)-catalyzed and acid-promoted highly regioselective oxidation of tautomerizable C(sp)-H bonds adjacent to the C-1 positions of various 1-Bn-DHIQs. It was observed that when 0.

Novel Stereoselective Syntheses of (+)-Streptol and (-)-1-Streptol Starting from Naturally Abundant (-)-Shikimic Acid.

Novel highly stereoselective syntheses of (+)-streptol and (-)-1--streptol starting from naturally abundant (-)-shikimic acid were described in this article. (-)-Shikimic acid was first converted to the common key intermediate by 11 steps in 40% yield. It was then converted to (+)-streptol by three steps in 72% yield, and it was also converted to (-)-1--streptol by one step in 90% yield.

Efficient and Highly Stereoselective Syntheses of (+)--Quercitol and (-)--Quercitol Starting from the Naturally Abundant (-)-Shikimic Acid.

Efficient and highly stereoselective syntheses of (+)--quercitol and (-)--quercitol starting from the naturally abundant (-)-shikimic acid were described in this article. (-)-Shikimic acid was first converted to the key intermediate by eight steps in 53% yield. It was then converted to (+)--quercitol by three steps in 78% yield and was also converted to (-)--quercitol by five steps in 63% yield.

Novel stereoselective syntheses of -octyl-β-valienamine (NOV) and -octyl-4--β-valienamine (NOEV) from (-)-shikimic acid.

-Octyl-β-valienamine (NOV) 1 and -octyl-4--β-valienamine (NOEV) 2 are potent chemical chaperone drug candidates for the therapy of lysosomal storage disorders. Novel stereoselective syntheses of NOV 1 and NOEV 2 starting from naturally abundant (-)-shikimic acid are described in this article. The common key intermediate compound 5 was first synthesized from readily available (-)-shikimic acid 9 steps in 50% yield.

Copper-Catalyzed Benign and Efficient Oxidation of Tetrahydroisoquinolines and Dihydroisoquinolines Using Air as a Clean Oxidant.

A green chemical method for mild oxidation of 1,2,3,4-tetrahydroisoquinolines (THIQs) and 3,4-dihydroisoquinolines (DHIQs) has been developed using air (O) as a clean oxidant. DHIQs and THIQs could be efficiently oxidized to isoquinolines in dimethyl sulfoxide at 25 °C under an open air atmosphere with CuBr (20 mol %) as the catalyst; different bases [NaOEt and/or 1,8-diazabicyclo[5,4,0]undec-7-ene] were used for the reaction according to the patterns of substituents (R, R).

Novel total syntheses of oxoaporphine alkaloids enabled by mild Cu-catalyzed tandem oxidation/aromatization of 1-Bn-DHIQs.

Novel total syntheses of oxoaporphine alkaloids such as liriodenine, dicentrinone, cassameridine, lysicamine, oxoglaucine and -methylmoschatoline were developed. The key step of these total syntheses is Cu-catalyzed conversion of 1-benzyl-3,4-dihydro-isoquinolines (1-Bn-DHIQs) to 1-benzoyl-isoquinolines (1-Bz-IQs) tandem oxidation/aromatization. This novel Cu-catalyzed conversion has been studied in detail, and was successfully used for constructing the 1-Bz-IQ core.

Y chromosomes of 40% Chinese descend from three Neolithic super-grandfathers.

Demographic change of human populations is one of the central questions for delving into the past of human beings. To identify major population expansions related to male lineages, we sequenced 78 East Asian Y chromosomes at 3.9 Mbp of the non-recombining region, discovered >4,000 new SNPs, and identified many new clades.