Organocatalytic atroposelective synthesis of axially chiral styrenes

Abstract

Axially chiral compounds are widespread in biologically active compounds and are useful chiral ligands or organocatalysts in asymmetric catalysis. It is well-known that styrenes are one of the most abundant and principal feedstocks and thus represent excellent prospective building blocks for chemical synthesis. Driven by the development of atroposelective synthesis of axially chiral styrene derivatives, we discovered herein the asymmetric organocatalytic approach via direct Michael addition reaction of substituted diones/ketone esters/malononitrile to alkynals. The axially chiral styrene compounds were produced with good chemical yields, enantioselectivities and almost complete E/Z-selectivities through a secondary amine-catalysed iminium activation strategy under mild conditions. Such structural motifs are important precursors for further transformations into biologically active compounds and synthetic useful intermediates and may have potential applications in asymmetric synthesis as olefin ligands or organocatalysts.

Multi-Domain Translation between Single-Cell Imaging and Sequencing Data using Autoencoders

“…Moreover, linking genome organization with gene expression generates hypotheses that can be tested experimentally to validate our methodology. We first analyzed single-cell RNA-seq data of human blood cells from (21) and used known markers to identify naive (CD4+) and activated T-cells (Fig 2a and Fig S2, Table S3, Data S1). An in-depth analysis of the naive T-cell population revealed two distinct subpopulations that were robust to various clustering strategies (Fig 2b and Fig S3, Data S1).…”

Enantioselective Construction of Axially Chiral Amino Sulfide Vinyl Arenes by Chiral Sulfide‐Catalyzed Electrophilic Carbothiolation of Alkynes

“…[6b] Owing to the importance of axially chiral compounds, a large number of catalytic enantioselective synthetic methods have been developed for their synthesis. [7][8][9][10][11][12][13][14][15][16] Most of them are focused on the synthesis of axially chiral biaryl compounds including transition-metal-catalyzed aryl-aryl crosscoupling, [7b, 8] oxidative couplings, [9] kinetic resolution, [10] desymmetrization, [11] point-to-axial chirality transfer, [12] de novo construction of an aromatic ring, [13] Cu-catalyzed ring-opening reaction of diaryliodonium salts, [14] and others. [15] To meet the requirements of broader substitution patterns and structural diversity, attention has been paid to the development of catalytic enantioselective methods for the synthesis of axially chiral compounds based on a dihydro-naphthyl-naphthyl skeleton with different starting materials in recent years.…”

High-density spatial transcriptomics arrays for in situ tissue profiling

“…In recent years, methods for both single-cell and spatial profiling have advanced dramatically 1 , especially those focused on the transcriptome. In particular, massively parallel single-cell RNA-Seq (scRNA-Seq) 5,6 can profile hundreds of thousands of dissociated individual cells, but does not directly recover the spatial position of those cells. In addition, it requires dissociation and cell manipulation, which can be difficult to perform; may require fresh tissue; and can introduce biases that lead to an altered molecular state or incomplete recovery of the tissue's cellular constituents 7 .…”

“…We thus enhanced the signal by light binning, through pooling of reads within a short range (e.g., 5X compared to the 5x5 hexagonal wells). On average, each bin had observations from 3.5±1.9 (mean±sd) (x,y) beads and 6 10.7±9.1 (mean±sd) overall UMIs. Finally, we assigned each "enhanced" bin to a layer, and robustly identified differentially expressed (DE) genes between the morphological layers (Methods).…”

“…UMIs per bin), we performed a two-sided t-test (FDR<0.1), identifying DE signatures specific to 6 morphological layers ( Fig. 1c, Supplementary Table 2, Supplementary Fig.…”