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Stereoconvergent reactions enable the transformation of mixed stereoisomers into well-defined, chiral products─a crucial strategy for handling Z / E -mixed olefins, which are common but challenging substrates in organic synthesis. Herein, we report a stereoconvergent and highly enantioselective method for synthesizing Z -homoallylic alcohols via the nickel-catalyzed reductive coupling of Z / E -mixed 1,3-dienes with aldehydes. This process is enabled by an N -heterocyclic carbene ligand characterized by C 2 -symmetric backbone chirality and bulky 2,6-diisopropyl N -aryl substituents. Our method achieves excellent stereocontrol over both enantioselectivity and Z -selectivity in a single step, producing chiral Z -homoallylic alcohols that are valuable in natural products and pharmaceuticals.

The development of the nervous system is coordinately regulated by multiple interacting factors. If a certain factor is altered or mutated, the coordinated developmental processes could be disrupted, resulting in neurological diseases. The 5-hydroxymethylcytosine (5hmC) is an intermediate product of the DNA demethylation processes. 5hmC and its metabolic enzymes, the ten-eleven translocation protein-TET family of dioxygenases, have recently been identified as new epigenetic players important in the regulation of the nervous system development, as well as in cognition, memory and other neurological functions. In various studies on neurodevelopment and neurodegeneration related diseases, the levels of 5hmC and TET proteins could be differentially regulated during development and/or disease pathogenesis, suggesting the potentially critical roles of 5hmC and TETs in these neural developmental and disease processes. In this review, we summarize the recent advances in research on 5hmC and TET dioxygenases in the regulation of neurodevelopment and neurological diseases, thereby providing significant insights on the involvements of 5hmC and TETs in neurodevelopment and on establishing new therapeutic strategies for human neurological diseases.

5-hydroxymethylcytosine (5hmC) is a naturally existing component in mammalian genomic DNA and is regarded as the sixth DNA base. Accumulating studies have revealed the essential role of 5hmC in embryonic development, brain function and cancer research. Compared to another well-known cytosine methylation derivate, 5-methylcytosine (5mC), the detection of 5hmC is difficult for its lower lever existing in most tissues. To distinguish 5hmC from other cytosine derivates, the methods using chemical or enzymatic DNA treatment, have been applied in targeted 5hmC detection or non-targeted 5hmC enrichment. Therefore, profiling DNA hydroxymethylcytosine by sensitive, accurate and reliable method is crucial for epigenetic study. This review discusses the principles behind recently developed techniques for 5hmC quantification and mapping. By comparing the advantages and shortcomings of these methods, the general guidelines were provided on how to select appropriate methods for specific experimental contexts.