56888-56-3Relevant academic research and scientific papers
Catalytic enantioselective allyl- and crotylboration of aldehydes using chiral diol·SnCl4 complexes. Optimization, substrate scope and mechanistic investigations
Rauniyar, Vivek,Zhai, Huimin,Hall, Dennis G.
supporting information; experimental part, p. 8481 - 8490 (2009/02/02)
We report a novel class of C2-symmetric chiral diols derived from the hydrobenzoin skeleton. The combination of these diols with SnCl 4 under Yamamoto's concept of Lewis acid assisted Bronsted acidity (LBA catalysis) leads to high levels of asymmetric induction in the allylboration of aldehydes by commercially available allylboronic acid pinacol ester 1a. The corresponding homoallylic alcohol products of synthetically useful aliphatic aldehydes are obtained in excellent yields with up to 98:2 er. This combined acid manifold is also efficient in catalyzing the diastereo- and enantioselective crotylboration of aldehydes, thus providing the propionate units in >95:5 dr and up to 98:2 er. The X-ray crystal structure of the optimal diol·SnCl4 complex, Vivol (4m)·SnCl 4, unambiguously shows the Bronsted acidic character of this LBA catalyst and its highly dissymmetrical environment. Further controls have ruled out a possible boron transesterification mechanism with the chiral diol and point to LBA catalyst-derived activation of the pinacol allylic boronates 1. Due to slow dissociation of the diol·SnCl4 complex, a small excess of diol is required in order to suppress a competing racemic cycle catalyzed by free SnCl4.
Convenient preparation of cycloalkenyl boronic acid pinacol esters
Rauniyar, Vivek,Zhai, Huimin,Hall, Dennis G.
experimental part, p. 3984 - 3995 (2009/04/11)
A practical method for the preparation of cycloalkenyl boronic acid pinacol esters is described. These important synthetic intermediates are typically made using more expensive methods like transition metal-catalyzed borylation of alkenyl halides or trifl
Discovery of 2-aminothiazole-4-carboxamides, a novel class of muscarinic M3 selective antagonists, through solution-phase parallel synthesis
Sagara, Yufu,Mitsuya, Morihiro,Uchiyama, Minaho,Ogino, Yoshio,Kjmura, Toshifumi,Ohtake, Norikazu,Mase, Toshiaki
, p. 437 - 440 (2007/10/03)
Synthesis and structure-activity relationship of a new class of muscarinic M3 selective antagonists were described. In the course of searching for a muscarinic M3 antagonist with a structure distinct from those of the 2-(4,4-difluorocyclopentyl)-2-phenylacetamide derivatives, we identified a thiazole-4-carboxamide derivative (1) as a lead compound in our in-house chemical collection. Since this compound (1) showed relatively low binding affinity (K1 = 140 nM) for M3 receptors in the human binding assays, we tried to improve its potency and selectivity for M 3 over M1 and M2 receptors by derivatization of 1 through a combinatorial approach. A solution-phase parallel synthesis effectively contributed to the optimization of each segment of 1. Thus, we have identified a cyclooctenylmethyl derivative (3e) and a cyclononenylmethyl derivative (3f) as representative M3 selective antagonists in this class.
Structure-activity relationships of xanthene carboxamides, novel CCR1 receptor antagonists
Naya, Akira,Ishikawa, Makoto,Matsuda, Kenji,Ohwaki, Kenji,Saeki, Toshihiko,Noguchi, Kazuhito,Ohtake, Norikazu
, p. 875 - 884 (2007/10/03)
The structure-activity relationships of xanthene carboxamide derivatives on the CCR1 receptor binding affinity and the functional antagonist activity were described. Previously, we reported a quaternarized xanthen-9-carboxamide 1 as a potent human CCR1 receptor antagonist that was derived from a xanthen-9-carboxamide lead 2a. Further derivatization of 2a focusing on installing an additional substituent into the xanthene ring resulted in the identification of 2b-1 with IC50 values of 1.8 nM and 13 nM in the binding assay using human CCR1 receptors transfected CHO cells and in the functional assay using U937 cells expressing human CCR1 receptors, respectively.
Cyclic compounds and uses thereof
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, (2008/06/13)
Compounds of general formula (1) R1—X1—W—X2—Z1—Z2—R2 or salts thereof, exhibiting preventive and therapeutic effects against HIV infectious diseases wherein R1is an optionally substituted five- or six-membered ring group; X1is a free valency or the like; W is a divalent group represented by, e. g., general formula (2) (wherein A and B are each an optionally substituted five- to seven-membered ring; E1and E4are each optionally substituted carbon or the like; E2and E3are each oxygen or the like; and a and b are each a single bond or a double bond); X2is a divalent group constituting a straight chain moiety; Z1is a divalent cyclic group or the like; Z2is a free valency or the like; and R2is optionally substituted amino or the like.
CYCLIC COMPOUNDS AND USES THEREOF
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Example 97, (2010/01/31)
Compounds of general formula (1) or salts thereof, exhibiting preventive and therapeutic effects against HIV infectious diseases wherein R1 is an optionally substituted five- or six-membered ring group; X1 is a free valency or the like; W is a divalent group represented by, e. g., general formula (2) (wherein A and B are each an optionally substituted five-to seven-membered ring; E1 and E4 are each optionally substituted carbon or the like; E2 and E3 are each oxygen or the like; and a and b are each a single bond or a double bond); X2 is a divalent group constituting a straight chain moiety; Z1 is a divalent cyclic group or the like; Z2 is a free valency or the like; and R2 is optionally substituted amino or the like.
Chemokine receptor antagonists
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, (2008/06/13)
PCT No. PCT/JP97/02548 Sec. 371 Date Jan. 29, 1999 Sec. 102(e) Date Jan. 29, 1999 PCT Filed Jul. 23, 1997 PCT Pub. No. WO98/04554 PCT Pub. Date Feb. 5, 1998The present invention relates to a compound of the general formula: wherein each of R1 and R2 which
