Asymmetric α-Alkylation of Aldehydes, Ketones, and Carboxylic …
2013年9月24日 · The asymmetric α-alkylation of aldehydes, ketones, and carboxylic acids is firmly entrenched as a fundamental method for the stereocontrolled synthesis of natural products and drugs. Despite its long history, important developments in the field continue to appear in the literature, as do numerous instances of its use in total synthesis.
Ketone - Wikipedia
One broad classification subdivides ketones into symmetrical and unsymmetrical derivatives, depending on the equivalency of the two organic substituents attached to the carbonyl center. Acetone and benzophenone ((C6H5)2CO) are symmetrical ketones. Acetophenone (C6H5C (O)CH3) is an unsymmetrical ketone.
Direct Asymmetric Alkylation of Ketones: Still Unconquered
2017年5月12日 · Herein we describe the state-of-the-art in terms of direct alkylation reactions of some carbonyl groups. We outline the limited progress that has been made with ketones, and potential routes towards ultimately achieving a widely applicable methodology for the asymmetric alkylation of ketones.
Authentic gambeson making : r/ArmsandArmor - Reddit
2020年4月21日 · While today in common talk gambeson is the standard term for the padded garment under maille, some texts indicate gambesons worn both above and below, some indicate that the aketon is to be worn under armour, and gambeson above -- forour purposes, I'm just going to lump all padded garments under armour as gambesons for ease.
Gambeson - Wikipedia
A gambeson (similar to the aketon, padded jack, pourpoint, or arming doublet) is a padded defensive jacket, worn as armour separately, or combined with mail or plate armour. Gambesons were produced with a sewing technique called quilting that produced a padded cloth.
Biocatalytic asymmetric aldol addition into unactivated ketones
2024年9月27日 · Our results reveal how aldolases are limited by kinetically favourable proton transfer with solvent, which undermines aldol addition into ketones. We show how a transaldolase can circumvent this...
Dynamic Kinetic Resolution of α-Keto Esters via Asymmetric …
2012年4月17日 · The dynamic kinetic resolution of β-aryl α-keto esters has been accomplished using a newly designed (arene)RuCl (monosulfonamide) transfer hydrogenation catalyst. This dynamic process generates three contiguous stereocenters with remarkable diastereoselectivity through a reduction/lactonization sequence.
Gambeson: warrior's best friend - Armstreet.com
2018年10月25日 · Often used as armor unto itself or as padded under armor, the gambeson (aka aketon or arming doublet) was a vital part of a medieval soldier or knight’s equipment since the X century. Miniature from a Book of Hours (c. 1380?) Despite being made of soft material, a thick enough gambeson provides excellent protection.
Asymmetric construction of acyclic quaternary stereocenters …
2021年11月18日 · Herein, an efficient chiral phosphoric acid catalyzed direct asymmetric addition of α-alkynyl acyclic ketones with allenamides has been developed, furnishing the acyclic all-carbon quaternary...
Asymmetric alkylation of .beta.-keto esters with optically active ...
Asymmetric alkylation of α-alkyl β-keto esters to α,α-dialkyl β-keto esters having either (R)- or (S)-chiral quaternary center depending on the solvent system. Tetrahedron 1993 , 49 (8) , 1579-1588.