Diastereoselective allylation and crotylation of N-unsubstituted imines derived from ketones
作者:Bhartesh Dhudshia、Jorge Tiburcio、Avinash N. Thadani
DOI:10.1039/b511411j
日期:——
A wide variety of tertiary carbinamines are synthesized in high yields via diastereoselective allylation and crotylation of in situ generated N-unsubstituted ketimines.
通过立体选择性的烯丙基化和巴豆基化反应,在原位生成了未取代的N-酮亚胺,进而高效合成了多种叔碳胺。
Potassium allyl- and crotyltrifluoroborates: Stable and efficient agents for allylation and crotylation
作者:Robert A. Batey、Avinash N. Thadani、David V. Smil
DOI:10.1016/s0040-4039(99)00774-1
日期:1999.6
Potassium allyl- and crotyltrifluoroborates react rapidly with aldehydes in the presence of BF3·Et2O. These salts are stable to air and moisture, and lead to adducts in high yield and with high diastereoselectivity. The stereochemistry of the crotylated products is consistent with the reaction via allylboron difluoride and a Zimmerman-Traxler like transition state.
3-cyclohexenols and -cyclopentenol based on Pd0-catalyzed alkylative, arylative, alkenylative, alkynylative, and borative cyclization reaction of allene−carbonyl compounds. Microwave irradiation increases not only the reaction rate but also the product yield by suppressing formation of hydroarylation byproducts observed in the same catalytic system. Cyclization of optically active 1,3-disubstituted allene aldehyde
Synthesis, Structure and Reactivities of Pentacoordinated Phosphorus–Boron Bonded Compounds
作者:Nathan J. O'Brien、Naokazu Kano、Nizam Havare、Ryohei Uematsu、Romain Ramozzi、Keiji Morokuma
DOI:10.1002/ejic.202000229
日期:2020.5.29
bicyclic compound or it could act as a mono‐hydroboration reagent. The hydroboration reactivity of the intermediate was found to be higher towards alkynes vs. alkenes, with good to moderate regioselectivity towards the terminal carbon. The second compound, a phosphoranyl‐triarylborate, was found to have different reactivity as it was highly stable towards acids and bases. This is thought to be due
An expeditious route to sterically encumbered nonproteinogenic α-amino acid precursors using allylboronic acids
作者:Samrat Sahu、Ganesh Karan、Lisa Roy、Modhu Sudan Maji
DOI:10.1039/d1sc06259j
日期:——
non-proteinogenic α-amino acid precursors in good yields and diastereoselectivities. Gram-scale synthesis, broad tolerance of functional groups, excellent stereodivergence, post-synthetic modifications, and easy removal of the chiral auxiliary are some of the key highlights. The protocol is applicable to various amino acids and short peptides, resulting in the incorporation of these precursors at the N-terminal
开发了使用烯丙基硼酸对N-叔丁烷亚磺酰基 α-亚氨基酯进行非对映选择性烯丙基化,以获得具有良好收率和非对映选择性的光学活性非蛋白原 α-氨基酸前体。革兰氏规模合成、广泛的官能团耐受性、出色的立体发散性、合成后修饰以及手性助剂的轻松去除是其中的一些关键亮点。该协议适用于各种氨基酸和短肽,导致这些前体在 N 端位置的结合。