Comments for one in ten thousand http://walkerma.wordpress.com A medicinal chemist searching for that needle in a haystack Mon, 08 Jun 2009 17:33:54 +0000 http://wordpress.com/ hourly 1 Comment on Word of the week…Racemate by nearlynothingbutnovels http://walkerma.wordpress.com/2007/03/29/word-of-the-weekracemate/#comment-9351 nearlynothingbutnovels Mon, 08 Jun 2009 17:33:54 +0000 http://walkerma.wordpress.com/2007/03/29/word-of-the-weekracemate/#comment-9351 I just stopped back to have a look at this page. The post and discussion are fascinating. One thing that confuses me, though, is the issue of density vs. solubility. How (or why) are these supposed to be related? What am I missing? Here is the reference I mentioned above: A new route to chiral bis-tertiary phosphine ligands: synthesis, resolution, and crystal structure of trans-bis-1,2-(diphenylphosphino)cyclopentane and the nickel adduct [trans-1,2-(PPh2)2C5H8]NiBr2. Allen, David L. et al. Journal of the Chemical Society, Chemical Communications (1983), (16), 895-6. CODEN: JCCCAT ISSN: 0022-4936. Journal written in English. CAN 100:34631 AN 1984:34631 CAPLUS Abstract Grignard reaction of PhMgBr with diphosphinocyclopentane I (R = Cl), prepd. by heating white P, PCl3 and cyclopentene at 200, gave I (R = Ph) (II). II with NiBr2 in 95% aq. EtOH gave the II.NiBr2 complex (III). Crystn. of III from CH2Cl2 gave crystals of (+)- and (-)-III.CH2Cl2, which were sepd. by hand picking. Treatment of (+)-III.CH2Cl2 with NaCN gave (-)-II. (-)-II with [RhLCl]2 (L = 1,4-cyclooctadiene) catalyzed the hydrogenation of methyl(N-benzoyl)- and (N-benzoyl)dehydrophenylalanine to give hydrogenated products of .apprx.100% optical purity. The crystal structures of II and III.CH2Cl2 are reported. I just stopped back to have a look at this page. The post and discussion are fascinating. One thing that confuses me, though, is the issue of density vs. solubility. How (or why) are these supposed to be related? What am I missing?

Here is the reference I mentioned above:

A new route to chiral bis-tertiary phosphine ligands: synthesis, resolution, and crystal structure of trans-bis-1,2-(diphenylphosphino)cyclopentane and the nickel adduct [trans-1,2-(PPh2)2C5H8]NiBr2. Allen, David L. et al. Journal of the Chemical Society, Chemical Communications (1983), (16), 895-6. CODEN: JCCCAT ISSN: 0022-4936. Journal written in English. CAN 100:34631 AN 1984:34631 CAPLUS

Abstract

Grignard reaction of PhMgBr with diphosphinocyclopentane I (R = Cl), prepd. by heating white P, PCl3 and cyclopentene at 200, gave I (R = Ph) (II). II with NiBr2 in 95% aq. EtOH gave the II.NiBr2 complex (III). Crystn. of III from CH2Cl2 gave crystals of (+)- and (-)-III.CH2Cl2, which were sepd. by hand picking. Treatment of (+)-III.CH2Cl2 with NaCN gave (-)-II. (-)-II with [RhLCl]2 (L = 1,4-cyclooctadiene) catalyzed the hydrogenation of methyl(N-benzoyl)- and (N-benzoyl)dehydrophenylalanine to give hydrogenated products of .apprx.100% optical purity. The crystal structures of II and III.CH2Cl2 are reported.

]]> Comment on Seprated at birth by Kevin http://walkerma.wordpress.com/2007/09/01/seprated-at-birth/#comment-9326 Kevin Wed, 24 Sep 2008 23:45:44 +0000 http://walkerma.wordpress.com/2007/09/01/seprated-at-birth/#comment-9326 Excellent... Smithers the resemblance is amazing and funny Excellent… Smithers the resemblance is amazing and funny

]]> Comment on For Medicinal Purposes… by resistless http://walkerma.wordpress.com/2008/01/01/for-medicinal-purposes/#comment-9320 resistless Wed, 28 May 2008 17:12:32 +0000 http://walkerma.wordpress.com/2008/01/01/for-medicinal-purposes/#comment-9320 resistless says : I absolutely agree with this ! resistless says : I absolutely agree with this !

]]> Comment on For Medicinal Purposes… by pmgb http://walkerma.wordpress.com/2008/01/01/for-medicinal-purposes/#comment-9317 pmgb Sat, 26 Apr 2008 06:07:13 +0000 http://walkerma.wordpress.com/2008/01/01/for-medicinal-purposes/#comment-9317 I will show this to my wife (she hates beer and I love it).. I will show this to my wife (she hates beer and I love it)..

]]> Comment on August 15, 2007 by Roller Coaster Fan http://walkerma.wordpress.com/2007/08/15/august-15-2007/#comment-9314 Roller Coaster Fan Mon, 21 Apr 2008 19:28:44 +0000 http://walkerma.wordpress.com/2007/08/15/august-15-2007/#comment-9314 Oh please, you don't want to ban my favorite pasttime. What next?? smoking? Oh please, you don’t want to ban my favorite pasttime. What next?? smoking?

]]> Comment on For Medicinal Purposes… by hipster doofus http://walkerma.wordpress.com/2008/01/01/for-medicinal-purposes/#comment-9303 hipster doofus Thu, 13 Mar 2008 14:12:47 +0000 http://walkerma.wordpress.com/2008/01/01/for-medicinal-purposes/#comment-9303 That's what I'm talking about. That’s what I’m talking about.

]]> Comment on by gaussling http://walkerma.wordpress.com/2007/12/09/136/#comment-9298 gaussling Thu, 28 Feb 2008 20:22:01 +0000 http://walkerma.wordpress.com/2007/12/09/136/#comment-9298 I guess I'm going to have to find the paper to get the background. This is very interesting- thanks for posting on it. I guess I’m going to have to find the paper to get the background. This is very interesting- thanks for posting on it.

]]> Comment on For Medicinal Purposes… by mitchandre http://walkerma.wordpress.com/2008/01/01/for-medicinal-purposes/#comment-9213 mitchandre Fri, 11 Jan 2008 07:02:03 +0000 http://walkerma.wordpress.com/2008/01/01/for-medicinal-purposes/#comment-9213 Nice find! Nice find!

]]> Comment on Separated at birth… by First time commenter http://walkerma.wordpress.com/2007/12/16/separated-at-birth-4/#comment-8613 First time commenter Sun, 16 Dec 2007 22:19:36 +0000 http://walkerma.wordpress.com/2007/12/16/separated-at-birth-4/#comment-8613 Awesome! Best likeness yet. Awesome! Best likeness yet.

]]> Comment on Seprated at birth by hipster doofus http://walkerma.wordpress.com/2007/09/01/seprated-at-birth/#comment-7701 hipster doofus Fri, 16 Nov 2007 23:30:47 +0000 http://walkerma.wordpress.com/2007/09/01/seprated-at-birth/#comment-7701 Congratulations on your promotion. Well deserved and not easy to come by at your level. Congratulations on your promotion. Well deserved and not easy to come by at your level.

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