Hydrofluoromethylation of alkenes with fluoroiodomethane and beyond
作者:Sandrine M. Hell、Claudio F. Meyer、Sebastiano Ortalli、Jeroen B. I. Sap、Xuanxiao Chen、Véronique Gouverneur
DOI:10.1039/d1sc03421a
日期:——
for the direct hydrofluoromethylation of alkenes is reported for the first time. This straighforward silyl radical-mediated reaction utilises CH2FI as a non-ozone depleting reagent, traditionally used in electrophilic, nucleophilic and carbene-type chemistry, but not as a CH2F radical source. By circumventing the challenges associated with the high reduction potential of CH2FI being closer to CH3I than
首次报道了烯烃直接氢氟甲基化的方法。这种直接的甲硅烷基自由基介导的反应利用 CH 2 FI 作为非臭氧消耗试剂,传统上用于亲电、亲核和卡宾型化学,但不作为 CH 2 F 自由基源。通过规避与 CH 2 FI的高还原电位比 CF 3 I更接近 CH 3 I相关的挑战,并利用 C-I 键的有利键解离能,我们证明了原料缺电子烯烃被转化在 (Me 3 Si) 3的干预下,由净氢氟甲基化产生的产物蓝色 LED 激活下的 SiH。这种看似简单但功能强大的方法已扩展到一系列(卤)甲基自由基前体,包括 ICH 2 I、ICH 2 Br、ICH 2 Cl 和 CHBr 2 F,以及 CH 3 I 本身;因此后一种试剂能够直接加氢甲基化。这种多功能化学被应用于18 F-、13 C- 和 D- 标记的试剂以及复杂的生物相关烯烃,为药物化学和正电子发射断层扫描中的应用提供了五十多种产品。
Highly chemoselective hydrogenation method using novel finely dispersed palladium catalyst on silk-fibroin: its preparation and activity
作者:Takashi Ikawa、Hironao Sajiki、Kosaku Hirota
DOI:10.1016/j.tet.2004.11.080
日期:2005.2
as a reductant at room temperature to be the Pd(0) complex. Pd/Fib catalyzed chemoselective hydrogenation of acetylenes, olefins and azides in the presence of aromatic ketones and aldehydes, halides, N-Cbz protective groups and benzyl esters which are readily hydrogenated using Pd/C or Pd/C(en) as a catalyst.
METHOD FOR PRODUCING a-SUBSTITUTED CYSTEINE OR SALT THEREOF OR SYNTHETIC INTERMEDIATE OF a-SUBSTITUTED CYSTEINE
申请人:API Corporation
公开号:US20160083341A1
公开(公告)日:2016-03-24
According to the present invention, it becomes possible to perform a process for converting into an α-substituted cysteine represented by general formula (1) or a salt thereof at low cost and on an industrial scale by employing a process that is routed through a compound represented by general formula (3) to a compound represented by general formula (6). Particularly, by employing a process that is routed through a compound represented by general formula (7-2), it becomes possible to detach a tert-butyl protection group in a simple manner and to produce the compound represented by general formula (1) with high purity. Furthermore, by employing a process that is routed through tert-butylthiomethanol or a process that is routed through a compound represented by general formula (9), it becomes possible to produce a compound represented by general formula (2) without generating bischloromethylether that is an oncogenic substance. In the production of an α-substituted-D-cysteine or a salt thereof, it becomes possible to perform a process for converting the compound represented by general formula (2) into a compound represented by general formula (3S) in one step by allowing an enzyme or the like to act on the compound represented by general formula (2).
photocatalytic Giese‐type reaction with alkylsilicates bearing C,O‐bidentate ligands as stable alkyl radical precursors has been reported. The alkylsilicates were prepared in one step from organometallic reagents. Not only primary, secondary, and tertiary alkyl radicals, but also elusive methyl radicals, could be generated by using the present reaction system. The generated radicals were trapped by electron‐deficient
SULFONIUM SALT, RESIST COMPOSITION AND RESIST PATTERN FORMING PROCESS
申请人:SHIN-ETSU CHEMICAL CO., LTD.
公开号:US20160090355A1
公开(公告)日:2016-03-31
A sulfonium salt of formula (0-1) is provided wherein W is alkylene or arylene, R
01
is a monovalent hydrocarbon group, m is 0, 1 or 2, k is an integer: 0≦k≦5+4m, R
101
, R
102
and R
103
are a monovalent hydrocarbon group, or at least two of R
101
, R
102
and R
103
may bond together to form a ring with the sulfur atom, and L is a single bond, ester, sulfonic acid ester, carbonate or carbamate bond. A resist composition comprising the sulfonium salt as PAG exhibits a very high resolution when processed by EB and EUV lithography. A pattern with minimal LER is obtainable.