Switchable C–H Functionalization of N-Tosyl Acrylamides with Acryloylsilanes
摘要:
A controllable Rh-catalyzed protocol to access alkylation and akenylation-annulation off N-tosyl acrylamide with, acryloyl silane is reported. In contrast to the directing group or catalyst-dependent divergent sp(2) C-H alkylation/alkenylation the instrinsic property of acryloylsilane allows the switchable reaction manifold, thereby affording either alkylation or alkylation Products with slight modification of the reaction conditions.
we present a strategy for the formation of 2‐fluoro‐1,3‐diene derivatives via rhodium‐catalyzed direct C(sp2)—C(sp2) cross‐coupling of gem‐difluoroalkenes and acrylamides. By merging Rh(III)‐catalyzed C(sp2)–H bond activation and nucleophilic addition/F‐elimination of gem‐difluoroalkene, an efficient defluorinative vinylation reaction is uncovered, which leads to the generation of 2‐fluoro‐1,3‐dienes
OXA-SPIRODIPHOSPHINE LIGAND AND METHOD FOR ASYMMETRIC HYDROGENATION OF alpha, beta-UNSATURATED CARBOXYLIC ACIDS
申请人:SHENZHEN CATALYS TECHNOLOGY CO., LTD.
公开号:US20210340168A1
公开(公告)日:2021-11-04
The present invention provides an oxa-spirodiphosphine ligand having a structure of general Formula (I) below:
wherein in general Formula (I), R
1
, R
2
, R
3
and R
4
are the same, and are alkyl, alkoxy, aryl, aryloxy, or hydrogen, in which R
1
, R
2
, R
3
and R
4
may or may not form a ring, any two of them may form a ring, or a polycyclic ring may be formed between two pairs of them; R
5
and R
6
is alkyl, aryl, or hydrogen; and R
7
and R
8
is alkyl, benzyl, or aryl. The present invention also provides a method for asymmetric hydrogenation of α,β-unsaturated carboxylic acids. A complex of the oxa-spirodiphosphine ligand with ruthenium shows excellent activity and enantioselectivity in the asymmetric hydrogenation of various α,β-unsaturated carboxylic acids, with which a chiral carboxylic acid product can be obtained with an enantioselectivity up to 99%.