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Molecular ‘assembly lines’, in which organic molecules undergo iterative processes such as chain elongation and functional group manipulation, are found in many natural systems, including polyketide biosynthesis. Here we report the creation of such an assembly line using the iterative, reagent-controlled homologation of a boronic ester. This process relies on the reactivity of α-lithioethyl tri-isopropylbenzoate, which inserts into carbon–boron bonds with exceptionally high fidelity and stereocontrol; each chain-extension step generates a new boronic ester, which is immediately ready for further homologation. We used this method to generate organic molecules that contain ten contiguous, stereochemically defined methyl groups. Several stereoisomers were synthesized and shown to adopt different shapes—helical or linear—depending on the stereochemistry of the methyl groups. This work should facilitate the rational design of molecules with predictable shapes, which could have an impact in areas of molecular sciences in which bespoke molecules are required. The iterative, reagent-controlled homologation of a boronic ester is used to create an ‘assembly line’ capable of synthesizing organic molecules that contain ten contiguous, stereochemically defined methyl groups and which have different shapes depending on the stereochemistry of those groups. Assembly-line synthesis of defined complex molecules Biological systems have evolved sophisticated machinery for organic synthesis resembling molecular assembly-line processes. Until now chemists have been able to mimic this type of approach only to synthesize peptides and oligonucleotides, creating simple amide (C–N) or phosphate (P–O) bonds. These authors emulate nature by creating a molecular assembly line through iterative reagent-controlled homologations of boronic esters. The process relies on the reactivity of α-lithioethyl tri-ispopropylbenzoate, which inserts into carbon–boron bonds with high fidelity and stereocontrol. Each chain-extension step generates a new boronic ester, which is immediately ready for further homologation. They use this method to generate several organic molecules that contain ten contiguous, stereochemically defined methyl groups. This work is a step towards the rational design and synthesis of complex molecules with predictable shape.

Molecular 'assembly lines', in which organic molecules undergo iterative processes such as chain elongation and functional group manipulation, are found in many natural systems, including polyketide biosynthesis. Here we report the creation of such an assembly line using the iterative, reagent-controlled homologation of a boronic ester. This process relies on the reactivity of [alpha]-lithioethyl tri-isopropylbenzoate, which inserts into carbon-boron bonds with exceptionally high fidelity and stereocontrol; each chain-extension step generates a new boronic ester, which is immediately ready for further homologation. We used this method to generate organic molecules that contain ten contiguous, stereochemically defined methyl groups. Several stereoisomers were synthesized and shown to adopt different shapes--helical or linear--depending on the stereochemistry of the methyl groups. This work should facilitate the rational design of molecules with predictable shapes, which could have an impact in areas of molecular sciences in which bespoke molecules are required.

Molecular assembly lines, where molecules undergo iterative processes involving chain elongation and functional group manipulation are hallmarks of many processes found in Nature. We have sought to emulate Nature in the development of our own molecular assembly line through iterative homologations of boronic esters. Here we report a reagent (α-lithioethyl triispopropylbenzoate) which inserts into carbon-boron bonds with exceptionally high fidelity and stereocontrol. Through repeated iteration we have converted a simple boronic ester into a complex molecule (a carbon chain with ten contiguous methyl groups) with remarkably high precision over its length, its stereochemistry and therefore its shape. Different stereoisomers were targeted and it was found that they adopted different shapes (helical/linear) according to their stereochemistry. This work should now enable scientists to rationally design and create molecules with predictable shape, which could have an impact in all areas of molecular sciences where bespoke molecules are required.

[...]long-term relationships are at stake. Because the real audience is not management but shareholders.

I read with interest the article on the church in China on Jan. 3. 'It provides a fascinating glimpse of one, but only one, congregation. It prompted a bit of digging on my part. The China Program office of the Presbyterian Church (USA), located in New York City, and other sources...

After preaching, in an unfinishd sanctuary, I returned to the dwelling of the pastor. It was a bright summer day. We sat upon the porch of that secluded parsonage, and, in the unbroken of the Sabbath, enjoyed the lofty praise of their Creator, ofered up by the glorious \"ruler of the day,\" the gently blowing breeze, the springing grass, the opening flower, the bending fruit branch, the restless bird, the reposing herd, and the sweet chorus of ten thousand rustling forest leaves.

A beautiful feature of the opening year is the bestowal and reception of the gifts of friendship. These gifts, whatever form they take, whether perishable or durable; whether of intrinsic value or otherwise, form the golden link of friendly hearts.

We recently received, from Mr. Charles Kemper, Sen., of Madison co., Va., the sum of Twenty Dollard, the bequest of his late aged sister, Miss AGNESS KEMPER, to the American Bible Society. Miss K., we understand, was a devoted friend and student of the Bible. She was known by the name of \"the walking Concordance.\" By he industry and frugality she had saved twenty dollars, which...